diff --git a/__test__/Interest/line.test.ts b/__test__/Interest/line.test.ts
index 0d4799afb..90507c34f 100644
--- a/__test__/Interest/line.test.ts
+++ b/__test__/Interest/line.test.ts
@@ -42,3 +42,10 @@ test('直线相交', () =>
     pts = IntersectLineAndLine(l1, l2, IntersectOption.ExtendBoth);
     expect(pts.length).toBe(1);
 });
+
+
+test('直线参数', () =>
+{
+    let l1 = new Line(new Vector3(0, 0, 0), new Vector3(5, 5, 0));
+    expect(l1.GetClosestAtPoint(new Vector3(10, 10), false).param).toBe(1);
+});
diff --git a/src/DatabaseServices/Line.ts b/src/DatabaseServices/Line.ts
index 88dc99da4..27cc0e2c7 100644
--- a/src/DatabaseServices/Line.ts
+++ b/src/DatabaseServices/Line.ts
@@ -203,7 +203,7 @@ export class Line extends Curve
             else if (param > length)
             {
                 closestPt = this.EndPoint;
-                param = 1;
+                param = length;
             }
             else
                 closestPt = sp.add(direction.multiplyScalar(param));