diff --git a/Rs.DeweyTester/Entitys/SimulateTesterManager.cs b/Rs.DeweyTester/Entitys/SimulateTesterManager.cs
index 47afbb7..6198d72 100644
--- a/Rs.DeweyTester/Entitys/SimulateTesterManager.cs
+++ b/Rs.DeweyTester/Entitys/SimulateTesterManager.cs
@@ -61,9 +61,17 @@ namespace Rs.MotionPlat.Entitys
                 _start.Stop();
                 _btest = false;
                 testResult = $"1$";
-                Random rnd = new Random();
-                int randomNumber = rnd.Next(0, 100);
-                int res = randomNumber < (100-GlobalVar.SimulateTestYield) ? 0 : 1;
+                int res = 0;
+                if (GlobalVar.SimulateTestYield<100)
+                {
+                    Random rnd = new Random();
+                    int randomNumber = rnd.Next(0, 100);
+                    res = randomNumber < (100 - GlobalVar.SimulateTestYield) ? 0 : 1;
+                }
+                else
+                {
+                    res = 0;
+                }
                 testResult = $"Result#0#{res}#CsvInfo#FailItems#TestItems#BinInfo$";
             }
         }