diff --git a/src/services/transaction.ts b/src/services/transaction.ts
index d0016c24..fb4b0899 100644
--- a/src/services/transaction.ts
+++ b/src/services/transaction.ts
@@ -66,9 +66,9 @@ interface ITransactionProcessor {
 export const TRANSACTION_QUEUE_NAME = 'rgbpp-ckb-transaction-queue';
 
 class InvalidTransactionError extends Error {
-  public data: ITransactionRequest;
+  public data?: ITransactionRequest;
 
-  constructor(message: string, data: ITransactionRequest) {
+  constructor(message: string, data?: ITransactionRequest) {
     super(message);
     this.name = this.constructor.name;
     this.data = data;
@@ -317,21 +317,39 @@ export default class TransactionProcessor
     ]);
     // using for spv proof, we need to remove the witness data from the transaction
     const hexWithoutWitness = transactionToHex(BitcoinTransaction.fromHex(hex), false);
-    let signedTx = await appendCkbTxWitnesses({
+    const signedTx = await appendCkbTxWitnesses({
       ckbRawTx,
       btcTxBytes: hexWithoutWitness,
       rgbppApiSpvProof,
     })!;
 
-    // append the spore cobuild witness to the transaction if needed
+    return signedTx;
+  }
+
+  /**
+   * Append the spore cobuild witness to the transaction if needed
+   * @param signedTx - the signed CKB transaction
+   */
+  private async appendSporeCobuildWitnessIfNeed(signedTx: CKBRawTransaction, needPaymasterCell: boolean) {
     const sporeTypeDep = getSporeTypeDep(this.isMainnet);
     const hasSporeTypeDep = signedTx.cellDeps.some((cellDep) => {
       return serializeCellDep(cellDep) === serializeCellDep(sporeTypeDep);
     });
     if (hasSporeTypeDep) {
-      signedTx = await this.appendSporeCobuildWitness(signedTx);
-    }
+      // if paymaster cell is needed, we need to exchange the last two witnesses
+      // make sure the spore cobuild witness is the last witness
+      if (needPaymasterCell) {
+        const witnesses = signedTx.witnesses;
+        const len = witnesses.length;
+        if (len < 2) {
+          throw new InvalidTransactionError('Not enough spore transaction witnesses');
+        }
+        signedTx.witnesses = [...witnesses.slice(0, len - 2), witnesses[len - 1], witnesses[len - 2]];
+      }
 
+      const tx = await this.appendSporeCobuildWitness(signedTx);
+      return tx;
+    }
     return signedTx;
   }
 
@@ -354,7 +372,7 @@ export default class TransactionProcessor
     if (sporeLiveCells.length > 0) {
       signedTx.witnesses[signedTx.witnesses.length - 1] = generateSporeTransferCoBuild(
         sporeLiveCells,
-        signedTx.outputs,
+        signedTx.outputs.slice(0, 1),
       );
     }
     return signedTx;
@@ -446,6 +464,9 @@ export default class TransactionProcessor
         }
         this.cradle.logger.debug(`[TransactionProcessor] Transaction signed: ${JSON.stringify(signedTx)}`);
 
+        // append the spore cobuild witness to the transaction if needed
+        signedTx = await this.appendSporeCobuildWitnessIfNeed(signedTx, ckbVirtualResult.needPaymasterCell);
+
         const txHash = await this.cradle.ckb.sendTransaction(signedTx);
         job.returnvalue = txHash;
         this.cradle.logger.info(`[TransactionProcessor] Transaction sent: ${txHash}`);