diff --git a/web/app/components/workflow/hooks/use-workflow.ts b/web/app/components/workflow/hooks/use-workflow.ts
index 460e36ae60ab59..b201b28b88d14b 100644
--- a/web/app/components/workflow/hooks/use-workflow.ts
+++ b/web/app/components/workflow/hooks/use-workflow.ts
@@ -283,15 +283,12 @@ export const useWorkflow = () => {
     return isUsed
   }, [isVarUsedInNodes])
 
-  const checkParallelLimit = useCallback((nodeId: string) => {
+  const checkParallelLimit = useCallback((nodeId: string, nodeHandle = 'source') => {
     const {
-      getNodes,
       edges,
     } = store.getState()
-    const nodes = getNodes()
-    const currentNode = nodes.find(node => node.id === nodeId)!
-    const sourceNodeOutgoers = getOutgoers(currentNode, nodes, edges)
-    if (sourceNodeOutgoers.length > PARALLEL_LIMIT - 1) {
+    const connectedEdges = edges.filter(edge => edge.source === nodeId && edge.sourceHandle === nodeHandle)
+    if (connectedEdges.length > PARALLEL_LIMIT - 1) {
       const { setShowTips } = workflowStore.getState()
       setShowTips(t('workflow.common.parallelTip.limit', { num: PARALLEL_LIMIT }))
       return false
@@ -322,7 +319,7 @@ export const useWorkflow = () => {
     return true
   }, [t, workflowStore])
 
-  const isValidConnection = useCallback(({ source, target }: Connection) => {
+  const isValidConnection = useCallback(({ source, sourceHandle, target }: Connection) => {
     const {
       edges,
       getNodes,
@@ -331,7 +328,7 @@ export const useWorkflow = () => {
     const sourceNode: Node = nodes.find(node => node.id === source)!
     const targetNode: Node = nodes.find(node => node.id === target)!
 
-    if (!checkParallelLimit(source!))
+    if (!checkParallelLimit(source!, sourceHandle || 'source'))
       return false
 
     if (sourceNode.type === CUSTOM_NOTE_NODE || targetNode.type === CUSTOM_NOTE_NODE)
diff --git a/web/app/components/workflow/nodes/_base/components/next-step/add.tsx b/web/app/components/workflow/nodes/_base/components/next-step/add.tsx
index 6e3988eecb64b0..75694983cdcbd8 100644
--- a/web/app/components/workflow/nodes/_base/components/next-step/add.tsx
+++ b/web/app/components/workflow/nodes/_base/components/next-step/add.tsx
@@ -1,6 +1,7 @@
 import {
   memo,
   useCallback,
+  useState,
 } from 'react'
 import { useTranslation } from 'react-i18next'
 import {
@@ -10,6 +11,7 @@ import {
   useAvailableBlocks,
   useNodesInteractions,
   useNodesReadOnly,
+  useWorkflow,
 } from '@/app/components/workflow/hooks'
 import BlockSelector from '@/app/components/workflow/block-selector'
 import type {
@@ -30,9 +32,11 @@ const Add = ({
   isParallel,
 }: AddProps) => {
   const { t } = useTranslation()
+  const [open, setOpen] = useState(false)
   const { handleNodeAdd } = useNodesInteractions()
   const { nodesReadOnly } = useNodesReadOnly()
   const { availableNextBlocks } = useAvailableBlocks(nodeData.type, nodeData.isInIteration)
+  const { checkParallelLimit } = useWorkflow()
 
   const handleSelect = useCallback<OnSelectBlock>((type, toolDefaultValue) => {
     handleNodeAdd(
@@ -47,6 +51,13 @@ const Add = ({
     )
   }, [nodeId, sourceHandle, handleNodeAdd])
 
+  const handleOpenChange = useCallback((newOpen: boolean) => {
+    if (newOpen && !checkParallelLimit(nodeId, sourceHandle))
+      return
+
+    setOpen(newOpen)
+  }, [checkParallelLimit, nodeId, sourceHandle])
+
   const renderTrigger = useCallback((open: boolean) => {
     return (
       <div
@@ -73,6 +84,8 @@ const Add = ({
 
   return (
     <BlockSelector
+      open={open}
+      onOpenChange={handleOpenChange}
       disabled={nodesReadOnly}
       onSelect={handleSelect}
       placement='top'
diff --git a/web/app/components/workflow/nodes/_base/components/node-handle.tsx b/web/app/components/workflow/nodes/_base/components/node-handle.tsx
index bcd03d6a5ec56e..9a662366d472c5 100644
--- a/web/app/components/workflow/nodes/_base/components/node-handle.tsx
+++ b/web/app/components/workflow/nodes/_base/components/node-handle.tsx
@@ -132,9 +132,9 @@ export const NodeSourceHandle = memo(({
   }, [])
   const handleHandleClick = useCallback((e: MouseEvent) => {
     e.stopPropagation()
-    if (checkParallelLimit(id))
+    if (checkParallelLimit(id, handleId))
       setOpen(v => !v)
-  }, [checkParallelLimit, id])
+  }, [checkParallelLimit, id, handleId])
   const handleSelect = useCallback((type: BlockEnum, toolDefaultValue?: ToolDefaultValue) => {
     handleNodeAdd(
       {