diff --git a/frontend/src/features/providers/components/BatchAssignModelsDialog.vue b/frontend/src/features/providers/components/BatchAssignModelsDialog.vue
index 97243d3..a629bbd 100644
--- a/frontend/src/features/providers/components/BatchAssignModelsDialog.vue
+++ b/frontend/src/features/providers/components/BatchAssignModelsDialog.vue
@@ -433,11 +433,17 @@ const availableGlobalModels = computed(() => {
   )
 })
 
-// 计算可添加的上游模型（排除已关联的）
+// 计算可添加的上游模型（排除已关联的，包括主模型名和映射名称）
 const availableUpstreamModelsBase = computed(() => {
-  const existingModelNames = new Set(
-    existingModels.value.map(m => m.provider_model_name)
-  )
+  const existingModelNames = new Set<string>()
+  for (const m of existingModels.value) {
+    // 主模型名
+    existingModelNames.add(m.provider_model_name)
+    // 映射名称
+    for (const mapping of m.provider_model_mappings ?? []) {
+      if (mapping.name) existingModelNames.add(mapping.name)
+    }
+  }
   return upstreamModels.value.filter(m => !existingModelNames.has(m.id))
 })
 
diff --git a/frontend/src/features/providers/components/ModelMappingDialog.vue b/frontend/src/features/providers/components/ModelMappingDialog.vue
index 61c63ba..74b9ad0 100644
--- a/frontend/src/features/providers/components/ModelMappingDialog.vue
+++ b/frontend/src/features/providers/components/ModelMappingDialog.vue
@@ -449,7 +449,17 @@ interface UpstreamModelGroup {
 }
 
 const groupedAvailableUpstreamModels = computed<UpstreamModelGroup[]>(() => {
+  // 收集当前表单已添加的名称
   const addedNames = new Set(formData.value.aliases.map(a => a.name.trim()))
+
+  // 收集所有已存在的映射名称（包括主模型名和映射名称）
+  for (const m of props.models) {
+    addedNames.add(m.provider_model_name)
+    for (const mapping of m.provider_model_mappings ?? []) {
+      if (mapping.name) addedNames.add(mapping.name)
+    }
+  }
+
   const availableModels = filteredUpstreamModels.value.filter(m => !addedNames.has(m.id))
 
   const groups = new Map<string, UpstreamModelGroup>()