diff --git a/paddle/cinn/common/cas.cc b/paddle/cinn/common/cas.cc
index b72650301bbfe..6264c5b12d453 100644
--- a/paddle/cinn/common/cas.cc
+++ b/paddle/cinn/common/cas.cc
@@ -27,7 +27,6 @@
 #include "paddle/cinn/ir/utils/ir_nodes_collector.h"
 #include "paddle/cinn/ir/utils/ir_printer.h"
 #include "paddle/cinn/ir/utils/ir_visitor.h"
-#include "paddle/cinn/optim/cast_simplify.h"
 #include "paddle/cinn/utils/string.h"
 
 namespace cinn {
diff --git a/paddle/cinn/common/ir_util.cc b/paddle/cinn/common/ir_util.cc
index 97d56f2ceaeb4..f0f219ee105f7 100644
--- a/paddle/cinn/common/ir_util.cc
+++ b/paddle/cinn/common/ir_util.cc
@@ -21,7 +21,6 @@
 #include "paddle/cinn/ir/op/ir_operators.h"
 #include "paddle/cinn/ir/utils/ir_mutator.h"
 #include "paddle/cinn/ir/utils/ir_printer.h"
-#include "paddle/cinn/optim/cast_simplify.h"
 
 namespace cinn {
 namespace common {
@@ -147,7 +146,7 @@ Expr IndiceToAbsOffset(const std::vector<Expr> &shape,
   for (int i = 0; i < shape.size(); i++) {
     CHECK_EQ(shape[i].type(), Int(32));
     Expr indice_prod = indices[i];
-    optim::CastSimplify(&indice_prod);
+    optim::SimplifyCast(&indice_prod);
     for (int j = i + 1; j < shape.size(); j++) {
       indice_prod = RampRelatedMul(indice_prod, shape[j]);
     }
diff --git a/paddle/cinn/optim/CMakeLists.txt b/paddle/cinn/optim/CMakeLists.txt
index 45c38c2632717..99ae9cf3bd3d6 100755
--- a/paddle/cinn/optim/CMakeLists.txt
+++ b/paddle/cinn/optim/CMakeLists.txt
@@ -23,7 +23,6 @@ gather_srcs(
   compute_inline_expand.cc
   buffer_assign.cc
   replace_const_param_to_integer.cc
-  cast_simplify.cc
   lower_intrin.cc
   cast_bool_to_int8.cc
   collect_undefined_vars.cc
diff --git a/paddle/cinn/optim/cast_simplify.cc b/paddle/cinn/optim/cast_simplify.cc
deleted file mode 100644
index a6431e42e467c..0000000000000
--- a/paddle/cinn/optim/cast_simplify.cc
+++ /dev/null
@@ -1,117 +0,0 @@
-// Copyright (c) 2021 CINN Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "paddle/cinn/optim/cast_simplify.h"
-
-#include "paddle/cinn/ir/utils/ir_mutator.h"
-
-namespace cinn::optim {
-
-using cinn::common::bfloat16;
-using cinn::common::float16;
-
-namespace {
-
-template <typename CastType, typename T>
-CastType NormCastValue(T value) {
-  if (type_of<CastType>().is_uint() || type_of<T>().is_uint()) {
-    // not support uint
-    return static_cast<CastType>(value);
-  }
-
-  if (std::isinf(value)) {
-    return std::numeric_limits<CastType>::infinity();
-  } else if (std::isnan(value)) {
-    return std::numeric_limits<CastType>::signaling_NaN();
-  } else if (value >= static_cast<T>(std::numeric_limits<CastType>::max())) {
-    return std::numeric_limits<CastType>::max();
-  } else if (value <= static_cast<T>(std::numeric_limits<CastType>::lowest())) {
-    return std::numeric_limits<CastType>::lowest();
-  }
-  return static_cast<CastType>(value);
-}
-
-struct Mutator : ir::IRMutator<> {
-  using ir::IRMutator<>::Visit;
-
-  void Visit(const ir::Cast* op, Expr* expr) {
-    auto* node = expr->As<ir::Cast>();
-
-    Visit(&node->v(), &node->v());
-
-    if (op->type() == op->v().type()) {
-      *expr = op->v();
-      return;
-    }
-
-#define __CAST_TO_TYPE(type__)                                          \
-  if (auto* i = op->v().As<ir::IntImm>()) {                             \
-    *expr = Expr(static_cast<type__>(i->value));                        \
-  } else if (auto* f = op->v().As<ir::FloatImm>()) {                    \
-    *expr = Expr(static_cast<type__>(NormCastValue<type__>(f->value))); \
-  } else if (auto* u = op->v().As<ir::UIntImm>()) {                     \
-    *expr = Expr(static_cast<type__>(u->value));                        \
-  } else {                                                              \
-    CINN_NOT_IMPLEMENTED                                                \
-  }
-
-    if (op->v().is_constant()) {
-      if (op->type() == type_of<int8_t>()) {
-        __CAST_TO_TYPE(int8_t)
-      } else if (op->type() == type_of<int16_t>()) {
-        __CAST_TO_TYPE(int16_t)
-      } else if (op->type() == type_of<int32_t>()) {
-        __CAST_TO_TYPE(int32_t)
-      } else if (op->type() == type_of<int64_t>()) {
-        __CAST_TO_TYPE(int64_t)
-      } else if (op->type() == type_of<uint8_t>()) {
-        __CAST_TO_TYPE(uint8_t)
-      } else if (op->type() == type_of<uint16_t>()) {
-        __CAST_TO_TYPE(uint16_t)
-      } else if (op->type() == type_of<uint32_t>()) {
-        __CAST_TO_TYPE(uint32_t)
-      } else if (op->type() == type_of<uint64_t>()) {
-        __CAST_TO_TYPE(uint64_t)
-      } else if (op->type() == type_of<float>()) {
-        __CAST_TO_TYPE(float)
-      } else if (op->type() == type_of<double>()) {
-        __CAST_TO_TYPE(double)
-      } else if (op->type() == type_of<bool>()) {
-        __CAST_TO_TYPE(bool)
-      } else if (op->type() == type_of<uint32_t>()) {
-        __CAST_TO_TYPE(uint32_t)
-      } else if (op->type() == type_of<uint64_t>()) {
-        __CAST_TO_TYPE(uint64_t)
-      } else if (op->type() == type_of<bfloat16>()) {
-        // Cannot simplify!!! pass
-        __CAST_TO_TYPE(bfloat16)
-      } else if (op->type() == type_of<float16>()) {
-        // Cannot simplify!!! pass
-        __CAST_TO_TYPE(float16)
-      } else {
-        CINN_NOT_IMPLEMENTED
-      }
-    }
-#undef __CAST_TO_TYPE
-  }
-};
-
-}  // namespace
-
-void CastSimplify(Expr* e) {
-  Mutator mutator;
-  mutator.Visit(e, e);
-}
-
-}  // namespace cinn::optim
diff --git a/paddle/cinn/optim/cast_simplify.h b/paddle/cinn/optim/cast_simplify.h
deleted file mode 100644
index 072f39783d187..0000000000000
--- a/paddle/cinn/optim/cast_simplify.h
+++ /dev/null
@@ -1,31 +0,0 @@
-// Copyright (c) 2021 CINN Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#pragma once
-
-#include "paddle/cinn/ir/ir.h"
-
-namespace cinn::optim {
-
-/**
- * Simplify the Cast nodes.
- *
- * There are several patterns:
- * 1. the source and target type are the same, drop the Cast node
- * 2. for intermediate numbers, just replace the Cast node with a Node of the
- * target type
- */
-void CastSimplify(Expr* e);
-
-}  // namespace cinn::optim
diff --git a/paddle/cinn/optim/cast_simplify_test.cc b/paddle/cinn/optim/cast_simplify_test.cc
index 5b7a21bae86f4..57103db27f397 100644
--- a/paddle/cinn/optim/cast_simplify_test.cc
+++ b/paddle/cinn/optim/cast_simplify_test.cc
@@ -12,13 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "paddle/cinn/optim/cast_simplify.h"
-
 #include <gtest/gtest.h>
 
 #include "paddle/cinn/ir/op/ir_operators.h"
 #include "paddle/cinn/ir/utils/ir_printer.h"
-
+#include "paddle/cinn/optim/ir_simplify.h"
 namespace cinn::optim {
 
 TEST(CastSimplify, same_type) {
@@ -26,7 +24,7 @@ TEST(CastSimplify, same_type) {
   Expr a = ir::Cast::Make(Int(32), n);
   LOG(INFO) << n->type();
   LOG(INFO) << a;
-  CastSimplify(&a);
+  SimplifyCast(&a);
   ASSERT_EQ(utils::GetStreamCnt(a), "n");
 }
 
@@ -34,7 +32,7 @@ TEST(CastSimplify, Imm_int) {
   Expr a = ir::Cast::Make(Int(64), Expr(1));
   Expr c = ir::Cast::Make(Int(32), a);
   LOG(INFO) << c;
-  CastSimplify(&c);
+  SimplifyCast(&c);
   LOG(INFO) << c;
   ASSERT_EQ(utils::GetStreamCnt(c), "1");
   ASSERT_EQ(c.type(), Int(32));
@@ -44,7 +42,7 @@ TEST(CastSimplify, Imm_double) {
   Expr a = ir::Cast::Make(Float(64), Expr(2.33));
   Expr c = ir::Cast::Make(Int(32), a);
   LOG(INFO) << c;
-  CastSimplify(&c);
+  SimplifyCast(&c);
   LOG(INFO) << c;
   ASSERT_EQ(utils::GetStreamCnt(c), "2");
   ASSERT_EQ(c.type(), Int(32));
@@ -54,7 +52,7 @@ TEST(CastSimplify, Imm_uint) {
   Expr a = ir::Cast::Make(UInt(64), Expr(1));
   Expr c = ir::Cast::Make(UInt(32), a);
   LOG(INFO) << c;
-  CastSimplify(&c);
+  SimplifyCast(&c);
   LOG(INFO) << c;
   ASSERT_EQ(utils::GetStreamCnt(c), "1");
   ASSERT_EQ(c.type(), UInt(32));
diff --git a/paddle/cinn/optim/ir_simplify.cc b/paddle/cinn/optim/ir_simplify.cc
index 3c0f9298dae2c..bfed498da521d 100644
--- a/paddle/cinn/optim/ir_simplify.cc
+++ b/paddle/cinn/optim/ir_simplify.cc
@@ -29,13 +29,14 @@
 #include "paddle/cinn/ir/utils/ir_mutator.h"
 #include "paddle/cinn/ir/utils/ir_printer.h"
 #include "paddle/cinn/ir/utils/ir_visitor.h"
-#include "paddle/cinn/optim/cast_simplify.h"
 #include "paddle/cinn/utils/string.h"
 
 namespace cinn {
 namespace optim {
 using namespace ir;  // NOLINT
+using common::bfloat16;
 using common::ExprToGinacConverter;
+using common::float16;
 using utils::GetStreamCnt;
 using utils::Replace;
 
@@ -346,11 +347,95 @@ struct SimplifyForLoopsMutator : public ir::IRMutator<> {
   }
 };
 
+template <typename CastType, typename T>
+CastType NormCastValue(T value) {
+  if (type_of<CastType>().is_uint() || type_of<T>().is_uint()) {
+    // not support uint
+    return static_cast<CastType>(value);
+  }
+
+  if (std::isinf(value)) {
+    return std::numeric_limits<CastType>::infinity();
+  } else if (std::isnan(value)) {
+    return std::numeric_limits<CastType>::signaling_NaN();
+  } else if (value >= static_cast<T>(std::numeric_limits<CastType>::max())) {
+    return std::numeric_limits<CastType>::max();
+  } else if (value <= static_cast<T>(std::numeric_limits<CastType>::lowest())) {
+    return std::numeric_limits<CastType>::lowest();
+  }
+  return static_cast<CastType>(value);
+}
+
+struct SimplifyCastMutator : public ir::IRMutator<> {
+  void operator()(Expr* expr) { ir::IRMutator<ir::Expr*>::Visit(expr, expr); }
+
+  void Visit(const ir::Cast* op, Expr* expr) {
+    auto* node = expr->As<ir::Cast>();
+
+    ir::IRMutator<ir::Expr*>::Visit(&node->v(), &node->v());
+
+    if (op->type() == op->v().type()) {
+      *expr = op->v();
+      return;
+    }
+
+#define __CAST_TO_TYPE(type__)                                          \
+  if (auto* i = op->v().As<ir::IntImm>()) {                             \
+    *expr = Expr(static_cast<type__>(i->value));                        \
+  } else if (auto* f = op->v().As<ir::FloatImm>()) {                    \
+    *expr = Expr(static_cast<type__>(NormCastValue<type__>(f->value))); \
+  } else if (auto* u = op->v().As<ir::UIntImm>()) {                     \
+    *expr = Expr(static_cast<type__>(u->value));                        \
+  } else {                                                              \
+    CINN_NOT_IMPLEMENTED                                                \
+  }
+
+    if (op->v().is_constant()) {
+      if (op->type() == type_of<int8_t>()) {
+        __CAST_TO_TYPE(int8_t)
+      } else if (op->type() == type_of<int16_t>()) {
+        __CAST_TO_TYPE(int16_t)
+      } else if (op->type() == type_of<int32_t>()) {
+        __CAST_TO_TYPE(int32_t)
+      } else if (op->type() == type_of<int64_t>()) {
+        __CAST_TO_TYPE(int64_t)
+      } else if (op->type() == type_of<uint8_t>()) {
+        __CAST_TO_TYPE(uint8_t)
+      } else if (op->type() == type_of<uint16_t>()) {
+        __CAST_TO_TYPE(uint16_t)
+      } else if (op->type() == type_of<uint32_t>()) {
+        __CAST_TO_TYPE(uint32_t)
+      } else if (op->type() == type_of<uint64_t>()) {
+        __CAST_TO_TYPE(uint64_t)
+      } else if (op->type() == type_of<float>()) {
+        __CAST_TO_TYPE(float)
+      } else if (op->type() == type_of<double>()) {
+        __CAST_TO_TYPE(double)
+      } else if (op->type() == type_of<bool>()) {
+        __CAST_TO_TYPE(bool)
+      } else if (op->type() == type_of<uint32_t>()) {
+        __CAST_TO_TYPE(uint32_t)
+      } else if (op->type() == type_of<uint64_t>()) {
+        __CAST_TO_TYPE(uint64_t)
+      } else if (op->type() == type_of<bfloat16>()) {
+        // Cannot simplify!!! pass
+        __CAST_TO_TYPE(bfloat16)
+      } else if (op->type() == type_of<float16>()) {
+        // Cannot simplify!!! pass
+        __CAST_TO_TYPE(float16)
+      } else {
+        CINN_NOT_IMPLEMENTED
+      }
+    }
+#undef __CAST_TO_TYPE
+  }
+};
+
 }  // namespace
 
 void Simplify(Expr* expr) {
   VLOG(3) << "Begin Simplify " << *expr;
-  optim::CastSimplify(expr);
+  SimplifyCastMutator()(expr);
   SimplifyRampMutator()(expr);
   SimplifyLoadMutator()(expr);
   SimplifyStoreMutator()(expr);
@@ -363,6 +448,7 @@ void Simplify(Expr* expr) {
   ReplaceFracWithDivMutator()(expr);
 }
 
+void SimplifyCast(Expr* expr) { SimplifyCastMutator()(expr); }
 void SimplifyForLoops(Expr* expr) { SimplifyForLoopsMutator()(expr); }
 void SimplifyBlocks(Expr* expr) { SimplifyBlocksMutator()(expr); }
 
diff --git a/paddle/cinn/optim/ir_simplify.h b/paddle/cinn/optim/ir_simplify.h
index 1d6abf1cd9a9f..b0e695af53537 100644
--- a/paddle/cinn/optim/ir_simplify.h
+++ b/paddle/cinn/optim/ir_simplify.h
@@ -30,6 +30,8 @@ namespace optim {
  */
 void Simplify(Expr *expr);
 
+void SimplifyCast(Expr *expr);
+
 void SimplifyForLoops(Expr *expr);
 
 void SimplifyBlocks(Expr *expr);
diff --git a/paddle/cinn/optim/optimize.cc b/paddle/cinn/optim/optimize.cc
index 18db99df48e2b..b1e73e3c58a9b 100644
--- a/paddle/cinn/optim/optimize.cc
+++ b/paddle/cinn/optim/optimize.cc
@@ -19,7 +19,6 @@
 #include "paddle/cinn/ir/utils/ir_printer.h"
 #include "paddle/cinn/optim/call_arg_list_to_pod_value.h"
 #include "paddle/cinn/optim/cast_bool_to_int8.h"
-#include "paddle/cinn/optim/cast_simplify.h"
 #include "paddle/cinn/optim/eliminate_broadcast_in_forloop.h"
 #include "paddle/cinn/optim/extern_call_process.h"
 #include "paddle/cinn/optim/fold_cinn_call_arguments.h"