diff --git a/src/Geometry/CreateContour2.ts b/src/Geometry/CreateContour2.ts
index ac19a06cf..08f97b435 100644
--- a/src/Geometry/CreateContour2.ts
+++ b/src/Geometry/CreateContour2.ts
@@ -22,7 +22,7 @@ export function CreateContours(curves: Curve[], fuzz = 1e-4): Contour[]
     for (let cu of curves)
     {
         if (cu instanceof Circle)
-            contours.push(Contour.CreateContour(cu));
+            contours.push(Contour.CreateContour(cu.Clone()));//避免将原始曲线传递给板,导致撤销这个圆失败
         else if (cu instanceof Polyline)
             arrayPushArray(newCurves, cu.Explode());
         else if (cu instanceof Spline)