diff --git a/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/DecodeFunction.java b/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/DecodeFunction.java
index ad3ab2e0a2..9b1d25817c 100644
--- a/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/DecodeFunction.java
+++ b/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/DecodeFunction.java
@@ -44,9 +44,13 @@ public DecodeFunction(Function expr) {
 
     @Override
     public Object parse(SourceData sourceData, int rowIndex, Context context) {
-        String binaryString = OperatorTools.parseString(binaryParser.parse(sourceData, rowIndex, context));
-        String characterSetValue =
-                OperatorTools.parseString(characterSetParser.parse(sourceData, rowIndex, context)).toUpperCase();
+        Object binaryObj = binaryParser.parse(sourceData, rowIndex, context);
+        Object characterObj = characterSetParser.parse(sourceData, rowIndex, context);
+        if (binaryObj == null || characterObj == null) {
+            return null;
+        }
+        String binaryString = OperatorTools.parseString(binaryObj);
+        String characterSetValue = OperatorTools.parseString(characterObj).toUpperCase();
         return decode(binaryString, characterSetValue);
     }
 
diff --git a/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/EncodeFunction.java b/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/EncodeFunction.java
index 021f595079..ff6a8072ea 100644
--- a/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/EncodeFunction.java
+++ b/inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/EncodeFunction.java
@@ -44,9 +44,13 @@ public EncodeFunction(Function expr) {
 
     @Override
     public Object parse(SourceData sourceData, int rowIndex, Context context) {
-        String stringValue = OperatorTools.parseString(stringParser.parse(sourceData, rowIndex, context));
-        String characterSetValue =
-                OperatorTools.parseString(characterSetParser.parse(sourceData, rowIndex, context)).toUpperCase();
+        Object stringObj = stringParser.parse(sourceData, rowIndex, context);
+        Object characterObj = characterSetParser.parse(sourceData, rowIndex, context);
+        if (stringObj == null || characterObj == null) {
+            return null;
+        }
+        String stringValue = OperatorTools.parseString(stringObj);
+        String characterSetValue = OperatorTools.parseString(characterObj).toUpperCase();
         byte[] encodeBytes = encode(stringValue, characterSetValue);
         StringBuilder res = new StringBuilder();
         if (encodeBytes != null) {