diff --git a/TestProject/RNG/RandT.h b/TestProject/RNG/RandT.h
index f49eac7..ed8b941 100644
--- a/TestProject/RNG/RandT.h
+++ b/TestProject/RNG/RandT.h
@@ -20,7 +20,7 @@ double GuassRand(double mean = 0, double sigma = 0) {
       sqrt(-2 * log(U1)) * cos(2 * M_PI * U2);  // 均值为0，方差为1的正态分布
   double Y;
   if (sigma >= 0) {
-    Y = mean + sqrt(sigma) * Z;
+    Y = mean + sigma * Z;
   } else {
     Y = mean + Z;
   }