diff --git a/api/service/explorer/storage.go b/api/service/explorer/storage.go
index 18e6d5b5f..c17e6f8f6 100644
--- a/api/service/explorer/storage.go
+++ b/api/service/explorer/storage.go
@@ -180,6 +180,7 @@ type taskManager struct {
 func newTaskManager() *taskManager {
 	return &taskManager{
 		C: make(chan struct{}, numWorker),
+		T: make(chan *traceResult, numWorker),
 	}
 }
 
@@ -292,7 +293,7 @@ LOOP:
 			}
 		case traceData := <-bc.tm.T:
 			if exist, err := isTraceDataInDB(bc.db, traceData.hash); exist || err != nil {
-				break
+				continue
 			}
 			traceData.btc = bc.db.NewBatch()
 			_ = writeTraceData(traceData.btc, traceData.hash, traceData.data)
diff --git a/hmy/tracers/block_tracer.go b/hmy/tracers/block_tracer.go
index f8100aa61..4358027d9 100644
--- a/hmy/tracers/block_tracer.go
+++ b/hmy/tracers/block_tracer.go
@@ -186,7 +186,7 @@ func (c action) toJsonStr() (string, *string, *string) {
 	return "unkonw", nil, nil
 }
 
-type ParityBlockTracer struct {
+type ParityTxTracer struct {
 	blockNumber         uint64
 	blockHash           common.Hash
 	transactionPosition uint64
@@ -195,49 +195,54 @@ type ParityBlockTracer struct {
 	calls               []*action
 	action
 }
+type ParityBlockTracer struct {
+	cur     *ParityTxTracer
+	tracers []*ParityTxTracer
+}
 
-func (jst *ParityBlockTracer) push(ac *action) {
-	jst.calls = append(jst.calls, ac)
+func (ptt *ParityTxTracer) push(ac *action) {
+	ptt.calls = append(ptt.calls, ac)
 }
 
-func (jst *ParityBlockTracer) pop() *action {
-	popIndex := len(jst.calls) - 1
-	ac := jst.calls[popIndex]
-	jst.calls = jst.calls[:popIndex]
+func (ptt *ParityTxTracer) pop() *action {
+	popIndex := len(ptt.calls) - 1
+	ac := ptt.calls[popIndex]
+	ptt.calls = ptt.calls[:popIndex]
 	return ac
 }
 
-func (jst *ParityBlockTracer) last() *action {
-	return jst.calls[len(jst.calls)-1]
+func (ptt *ParityTxTracer) last() *action {
+	return ptt.calls[len(ptt.calls)-1]
 }
 
-func (jst *ParityBlockTracer) len() int {
-	return len(jst.calls)
+func (ptt *ParityTxTracer) len() int {
+	return len(ptt.calls)
 }
 
 // CaptureStart implements the ParityBlockTracer interface to initialize the tracing operation.
 func (jst *ParityBlockTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Address, create bool, input []byte, gas uint64, value *big.Int) error {
-	jst.op = vm.CALL // vritual call
+	jst.cur = &ParityTxTracer{}
+	jst.cur.op = vm.CALL // vritual call
 	if create {
-		jst.op = vm.CREATE // virtual create
+		jst.cur.op = vm.CREATE // virtual create
 	}
-	jst.from = from
-	jst.to = to
-	jst.input = input
-	jst.gas = gas
-	jst.value = (&big.Int{}).Set(value)
-	jst.blockHash = env.StateDB.BlockHash()
-	jst.transactionPosition = uint64(env.StateDB.TxIndex())
-	jst.transactionHash = env.StateDB.TxHash()
-	jst.blockNumber = env.BlockNumber.Uint64()
-	jst.descended = false
-	jst.push(&jst.action)
+	jst.cur.from = from
+	jst.cur.to = to
+	jst.cur.input = input
+	jst.cur.gas = gas
+	jst.cur.value = (&big.Int{}).Set(value)
+	jst.cur.blockHash = env.StateDB.BlockHash()
+	jst.cur.transactionPosition = uint64(env.StateDB.TxIndex())
+	jst.cur.transactionHash = env.StateDB.TxHash()
+	jst.cur.blockNumber = env.BlockNumber.Uint64()
+	jst.cur.descended = false
+	jst.cur.push(&jst.cur.action)
 	return nil
 }
 
 // CaptureState implements the ParityBlockTracer interface to trace a single step of VM execution.
 func (jst *ParityBlockTracer) CaptureState(env *vm.EVM, pc uint64, op vm.OpCode, gas, cost uint64, memory *vm.Memory, stack *vm.Stack, contract *vm.Contract, depth int, err error) error {
-	//if op < vm.CREATE && !jst.descended {
+	//if op < vm.CREATE && !jst.cur.descended {
 	//	return nil
 	//}
 	var retErr error
@@ -259,7 +264,7 @@ func (jst *ParityBlockTracer) CaptureState(env *vm.EVM, pc uint64, op vm.OpCode,
 	if op == vm.CREATE || op == vm.CREATE2 {
 		inOff := stackPeek(1).Int64()
 		inSize := stackPeek(2).Int64()
-		jst.push(&action{
+		jst.cur.push(&action{
 			op:      op,
 			from:    contract.Address(),
 			input:   memoryCopy(inOff, inSize),
@@ -267,11 +272,11 @@ func (jst *ParityBlockTracer) CaptureState(env *vm.EVM, pc uint64, op vm.OpCode,
 			gasCost: cost,
 			value:   (&big.Int{}).Set(stackPeek(0)),
 		})
-		jst.descended = true
+		jst.cur.descended = true
 		return retErr
 	}
 	if op == vm.SELFDESTRUCT {
-		ac := jst.last()
+		ac := jst.cur.last()
 		ac.push(&action{
 			op:      op,
 			from:    contract.Address(),
@@ -307,26 +312,26 @@ func (jst *ParityBlockTracer) CaptureState(env *vm.EVM, pc uint64, op vm.OpCode,
 		if op != vm.DELEGATECALL && op != vm.STATICCALL {
 			callObj.value = (&big.Int{}).Set(stackPeek(2))
 		}
-		jst.push(callObj)
-		jst.descended = true
+		jst.cur.push(callObj)
+		jst.cur.descended = true
 		return retErr
 	}
-	if jst.descended {
-		jst.descended = false
-		if depth >= jst.len() { // >= to >
-			jst.last().gas = gas
+	if jst.cur.descended {
+		jst.cur.descended = false
+		if depth >= jst.cur.len() { // >= to >
+			jst.cur.last().gas = gas
 		}
 	}
 	if op == vm.REVERT {
-		last := jst.last()
+		last := jst.cur.last()
 		last.err = errors.New("execution reverted")
 		revertOff := stackPeek(0).Int64()
 		revertLen := stackPeek(1).Int64()
 		last.revert = memoryCopy(revertOff, revertLen)
 		return retErr
 	}
-	if depth == jst.len()-1 { // depth == len - 1
-		call := jst.pop()
+	if depth == jst.cur.len()-1 { // depth == len - 1
+		call := jst.cur.pop()
 		if call.op == vm.CREATE || call.op == vm.CREATE2 {
 			call.gasUsed = call.gasIn - call.gasCost - gas
 
@@ -348,7 +353,7 @@ func (jst *ParityBlockTracer) CaptureState(env *vm.EVM, pc uint64, op vm.OpCode,
 				call.err = errors.New("internal failure")
 			}
 		}
-		jst.last().push(call)
+		jst.cur.last().push(call)
 	}
 	return retErr
 }
@@ -359,7 +364,7 @@ func (jst *ParityBlockTracer) CaptureFault(env *vm.EVM, pc uint64, op vm.OpCode,
 	if op == vm.REVERT {
 		return nil
 	}
-	call := jst.pop()
+	call := jst.cur.pop()
 	if call.err == nil {
 		// Consume all available gas and clean any leftovers
 		if call.gas != 0 {
@@ -367,35 +372,31 @@ func (jst *ParityBlockTracer) CaptureFault(env *vm.EVM, pc uint64, op vm.OpCode,
 		}
 
 		// Flatten the failed call into its parent
-		if jst.len() > 0 {
-			jst.last().push(call)
+		if jst.cur.len() > 0 {
+			jst.cur.last().push(call)
 			return nil
 		}
 	}
-	jst.push(call)
+	jst.cur.push(call)
 	return nil
 }
 
 // CaptureEnd is called after the call finishes to finalize the tracing.
 func (jst *ParityBlockTracer) CaptureEnd(output []byte, gasUsed uint64, t time.Duration, err error) error {
-	jst.output = output
-	jst.gasUsed = gasUsed
+	jst.cur.output = output
+	jst.cur.gasUsed = gasUsed
 	if err != nil {
-		jst.err = err
+		jst.cur.err = err
 	}
+	jst.tracers = append(jst.tracers, jst.cur)
 	return nil
 }
 
 // GetResult calls the Javascript 'result' function and returns its value, or any accumulated error
 func (jst *ParityBlockTracer) GetResult() ([]json.RawMessage, error) {
-	root := &jst.action
-	headPiece := fmt.Sprintf(
-		`"blockNumber":%d,"blockHash":"%s","transactionHash":"%s","transactionPosition":%d`,
-		jst.blockNumber, jst.blockHash.Hex(), jst.transactionHash.Hex(), jst.transactionPosition,
-	)
-
 	var results []json.RawMessage
 	var err error
+	var headPiece string
 	var finalize func(ac *action, traceAddress []int)
 	finalize = func(ac *action, traceAddress []int) {
 		typStr, acStr, outStr := ac.toJsonStr()
@@ -424,6 +425,13 @@ func (jst *ParityBlockTracer) GetResult() ([]json.RawMessage, error) {
 			finalize(subAc, append(traceAddress[:], i))
 		}
 	}
-	finalize(root, make([]int, 0))
+	for _, curTx := range jst.tracers {
+		root := &curTx.action
+		headPiece = fmt.Sprintf(
+			`"blockNumber":%d,"blockHash":"%s","transactionHash":"%s","transactionPosition":%d`,
+			curTx.blockNumber, curTx.blockHash.Hex(), curTx.transactionHash.Hex(), curTx.transactionPosition,
+		)
+		finalize(root, make([]int, 0))
+	}
 	return results, err
 }