diff --git a/web/app/components/workflow/nodes/start/components/var-item.tsx b/web/app/components/workflow/nodes/start/components/var-item.tsx
index 029547542e..e51cd79734 100644
--- a/web/app/components/workflow/nodes/start/components/var-item.tsx
+++ b/web/app/components/workflow/nodes/start/components/var-item.tsx
@@ -19,7 +19,7 @@ type Props = {
   className?: string
   readonly: boolean
   payload: InputVar
-  onChange?: (item: InputVar, moreInfo?: MoreInfo) => void
+  onChange?: (item: InputVar, moreInfo?: MoreInfo) => boolean
   onRemove?: () => void
   rightContent?: React.JSX.Element
   varKeys?: string[]
@@ -31,7 +31,7 @@ const VarItem: FC<Props> = ({
   className,
   readonly,
   payload,
-  onChange = noop,
+  onChange = () => true,
   onRemove = noop,
   rightContent,
   varKeys = [],
@@ -48,7 +48,9 @@ const VarItem: FC<Props> = ({
   }] = useBoolean(false)
 
   const handlePayloadChange = useCallback((payload: InputVar, moreInfo?: MoreInfo) => {
-    onChange(payload, moreInfo)
+    const isValid = onChange(payload, moreInfo)
+    if(!isValid)
+      return
     hideEditVarModal()
   }, [onChange, hideEditVarModal])
   return (
diff --git a/web/app/components/workflow/nodes/start/components/var-list.tsx b/web/app/components/workflow/nodes/start/components/var-list.tsx
index 024b50a759..a3c307bbd4 100644
--- a/web/app/components/workflow/nodes/start/components/var-list.tsx
+++ b/web/app/components/workflow/nodes/start/components/var-list.tsx
@@ -9,6 +9,8 @@ import { v4 as uuid4 } from 'uuid'
 import { ReactSortable } from 'react-sortablejs'
 import { RiDraggable } from '@remixicon/react'
 import cn from '@/utils/classnames'
+import { hasDuplicateStr } from '@/utils/var'
+import Toast from '@/app/components/base/toast'
 
 type Props = {
   readonly: boolean
@@ -28,7 +30,27 @@ const VarList: FC<Props> = ({
       const newList = produce(list, (draft) => {
         draft[index] = payload
       })
+      let errorMsgKey = ''
+      let typeName = ''
+      if(hasDuplicateStr(newList.map(item => item.variable))) {
+        errorMsgKey = 'appDebug.varKeyError.keyAlreadyExists'
+        typeName = 'appDebug.variableConfig.varName'
+      }
+
+      if(hasDuplicateStr(newList.map(item => item.label as string))) {
+        errorMsgKey = 'appDebug.varKeyError.keyAlreadyExists'
+        typeName = 'appDebug.variableConfig.labelName'
+      }
+
+      if (errorMsgKey) {
+        Toast.notify({
+          type: 'error',
+          message: t(errorMsgKey, { key: t(typeName) }),
+        })
+        return false
+      }
       onChange(newList, moreInfo ? { index, payload: moreInfo } : undefined)
+      return true
     }
   }, [list, onChange])
 
diff --git a/web/utils/var.ts b/web/utils/var.ts
index bdc2fbdd42..4bbb7ca631 100644
--- a/web/utils/var.ts
+++ b/web/utils/var.ts
@@ -45,7 +45,7 @@ export const getNewVarInWorkflow = (key: string, type = InputVarType.textInput)
   }
 }
 
-export const checkKey = (key: string, canBeEmpty?: boolean) => {
+export const checkKey = (key: string, canBeEmpty?: boolean, keys?: string[]) => {
   if (key.length === 0 && !canBeEmpty)
     return 'canNoBeEmpty'
 
@@ -82,6 +82,17 @@ export const checkKeys = (keys: string[], canBeEmpty?: boolean) => {
   return { isValid, errorKey, errorMessageKey }
 }
 
+export const hasDuplicateStr = (strArr: string[]) => {
+  const strObj: Record<string, number> = {}
+  strArr.forEach((str) => {
+    if (strObj[str])
+      strObj[str] += 1
+    else
+      strObj[str] = 1
+  })
+  return !!Object.keys(strObj).find(key => strObj[key] > 1)
+}
+
 const varRegex = /\{\{([a-zA-Z_]\w*)\}\}/g
 export const getVars = (value: string) => {
   if (!value)