diff --git a/__test__/Interfere/__snapshots__/intf.test.ts.snap b/__test__/Interfere/__snapshots__/intf.test.ts.snap
new file mode 100644
index 000000000..620dcdd20
--- /dev/null
+++ b/__test__/Interfere/__snapshots__/intf.test.ts.snap
@@ -0,0 +1,11 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`求交集错误 1`] = `2`;
+
+exports[`求交集错误 2`] = `1`;
+
+exports[`求交集错误 3`] = `"7704.00000"`;
+
+exports[`求交集错误 4`] = `"5771.53229"`;
+
+exports[`求交集错误 5`] = `"0.00000"`;
diff --git a/__test__/Interfere/intf.test.ts b/__test__/Interfere/intf.test.ts
new file mode 100644
index 000000000..d3026bade
--- /dev/null
+++ b/__test__/Interfere/intf.test.ts
@@ -0,0 +1,23 @@
+import { Polyline } from "../../src/api";
+import { Contour } from "../../src/DatabaseServices/Contour";
+import "../Utils/jest.util";
+import { LoadEntityFromFileData } from "../Utils/LoadEntity.util";
+
+test('求交集错误', () =>
+{
+    let d = [2, "Polyline", 8, 2, 0, false, 0, 7, 0, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1], 0, 0, true, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1], 0, 2, 4, [9.094947017729282e-12, -1411.0000000000002], 0, [9.094947017729282e-12, 2423], 0, [-17.999999999990905, 2423], 0, [-17.999999999990905, -1411.0000000000002], 0, true, "Polyline", 8, 2, 0, false, 0, 7, 0, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0.5140442132778844, 0, 0, 1], 0, 0, true, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0.5140442132778844, 0, 0, 1], 0, 2, 8, [540, 0], 0, [540, 102], 0, [552, 102], 0, [561, 2329], 0, [-0.5140442132778844, 2329], 0, [-0.5140442132778844, 2329], 0, [-0.5140442132778844, 2329], 0, [0, 0], 0, true];
+
+    let pls = LoadEntityFromFileData(d) as Polyline[];
+
+    let cons = pls.map(pl => Contour.CreateContour(pl));
+
+    let res = cons[0].GetIntersetAndUnionList(cons[1]);
+
+    expect(res.unionList.length).toMatchSnapshot();
+    expect(res.intersectionList.length).toMatchSnapshot();
+
+    for (let c of res.unionList)
+        expect(c.Length).toMatchNumberSnapshot();
+    for (let c of res.intersectionList)
+        expect(c.Length).toMatchNumberSnapshot();
+});
diff --git a/src/DatabaseServices/Entity/Polyline.ts b/src/DatabaseServices/Entity/Polyline.ts
index 390b85880..5cd709806 100644
--- a/src/DatabaseServices/Entity/Polyline.ts
+++ b/src/DatabaseServices/Entity/Polyline.ts
@@ -547,6 +547,8 @@ export class Polyline extends Curve
     }
     GetParamAtDist(dist: number): number
     {
+        if (equaln(dist, 0)) return 0;
+
         let cus = this.Explode();
         for (let i = 0; i < cus.length; i++)
         {