diff --git a/paddle/fluid/platform/debug_support.cc b/paddle/fluid/platform/debug_support.cc
index 77ff721020ee97cb2145b1086d512fa223b3c4cf..a46db932f6d6f35537aaaabee9bf409610981caa 100644
--- a/paddle/fluid/platform/debug_support.cc
+++ b/paddle/fluid/platform/debug_support.cc
@@ -23,8 +23,10 @@ template <>
 std::string PythonDebugSupport::Format() const {
   std::ostringstream sout;
   sout << "\nPython Callstacks: \n";
-  for (auto& line : info) {
-    sout << line;
+  if (!info.empty()) {
+    for (auto &line : info) {
+      sout << line;
+    }
   }
   return sout.str();
 }
diff --git a/paddle/fluid/platform/debug_support.h b/paddle/fluid/platform/debug_support.h
index 9d1d54cef7615a9a360aaa07cb69c800daf912ea..2c8ee6ed1f9a460eba98f24634a4e4c42c72894b 100644
--- a/paddle/fluid/platform/debug_support.h
+++ b/paddle/fluid/platform/debug_support.h
@@ -30,8 +30,8 @@ class DebugSupport {
  public:
   // Returns the singleton of DebugSupport.
   static DebugSupport* GetInstance() {
-    static std::unique_ptr<DebugSupport> debugSupport_(nullptr);
-    static std::once_flag init_flag_;
+    static thread_local std::unique_ptr<DebugSupport> debugSupport_(nullptr);
+    static thread_local std::once_flag init_flag_;
 
     std::call_once(init_flag_,
                    [&]() { debugSupport_.reset(new DebugSupport<T>()); });