diff --git a/__test__/Polyline/PointInPolyline.test.ts b/__test__/Polyline/PointInPolyline.test.ts
index a31786ee5..a20f06791 100644
--- a/__test__/Polyline/PointInPolyline.test.ts
+++ b/__test__/Polyline/PointInPolyline.test.ts
@@ -164,4 +164,19 @@ describe("", () =>
 
         expect(pl.PtInCurve(p)).toBeFalsy();
     });
+
+    test('精度过低导致的错误', () =>
+    {
+        let f = new CADFile();
+        f.Data =
+            [1, ["Polyline", 1, 1, 18237, false, 2, -1, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0.7938671363300003, 0.39666461398798525, 0, 1], 2, 5, [12.414545456418505, 8.796498405316765], 0, [12.015990240675425, 8.743859037199755], 0, [12.23362472371057, 8.552710046188702], 0, [12.233990240675425, 8.552758322014249], 0, [12.414545456418505, 8.796498405316765], 0, false]]
+
+        let p = new Vector3().fromArray([13.027857377005425, 8.947146562082409, 0]);
+
+        f.Read();
+        let pl = f.ReadObject() as Polyline;
+
+        pl.PtInCurve(p);//?
+    });
+
 })
diff --git a/src/DatabaseServices/PointInPolyline.ts b/src/DatabaseServices/PointInPolyline.ts
index b407e663a..06f7ab7cf 100644
--- a/src/DatabaseServices/PointInPolyline.ts
+++ b/src/DatabaseServices/PointInPolyline.ts
@@ -84,13 +84,13 @@ export function IsPointInPolyLine(pl: Polyline, pt: Vector3): boolean
             if (equal(pti, cu.StartPoint))
             {
                 let der = cu.GetFistDeriv(0);
-                if (der.x < -1e-3) //左边+ 右边0
+                if (der.x < -1e-4) //左边+ 右边0
                     crossings++;
             }
             else if (equal(pti, cu.EndPoint))
             {
                 let der = cu.GetFistDeriv(1);
-                if (der.x > 1e-3) //左边+ 右边0
+                if (der.x > 1e-4) //左边+ 右边0
                     crossings++;
             }
             else