diff --git a/mindspore/ccsrc/device/kernel_runtime_manager.cc b/mindspore/ccsrc/device/kernel_runtime_manager.cc
index 4fc6a622973724b02538ac0f5dc804ee609aecec..ca6f386b503fc7ce474a2e3556a02d80d2664a55 100644
--- a/mindspore/ccsrc/device/kernel_runtime_manager.cc
+++ b/mindspore/ccsrc/device/kernel_runtime_manager.cc
@@ -54,7 +54,7 @@ KernelRuntime *KernelRuntimeManager::GetSingleKernelRuntime(const std::string &d
     return runtime_iter->second.get();
   } else if (runtime_map_.size() > 0) {
     auto cur_runtime_key = runtime_map_.begin()->first;
-    if (!cur_runtime_key.empty()) {
+    if (cur_runtime_key.rfind('_') != std::string::npos) {
       auto cur_device_id = cur_runtime_key.substr(cur_runtime_key.rfind('_') + 1);
       MS_LOG(EXCEPTION) << "Can't change device id in runtime, already set device id: " << cur_device_id
                         << ", set device id: " << device_id << " failed";