diff --git a/__test__/Geometry/angleTo.test.ts b/__test__/Geometry/angleTo.test.ts
index b00b779e7..cd28d0249 100644
--- a/__test__/Geometry/angleTo.test.ts
+++ b/__test__/Geometry/angleTo.test.ts
@@ -37,3 +37,11 @@ test('变量补全', () =>
     let v = angleTo(new Vector3(1, 0, 0), new Vector3(0, 0, 1)); //?
     expect(v).toEqual(Math.PI * 0.5);
 });
+
+test('几乎平行的2向量', () =>
+{
+    let v1 = new Vector3(1);
+    let v2 = new Vector3(-1, 1.2246467991473532e-16, 5.041544910049491e-16);
+    let v = angleTo(v1, v2); //?
+    expect(v).toEqual(Math.PI);
+});
diff --git a/src/Geometry/GeUtils.ts b/src/Geometry/GeUtils.ts
index 40d3b85d6..68ee8ea75 100644
--- a/src/Geometry/GeUtils.ts
+++ b/src/Geometry/GeUtils.ts
@@ -97,7 +97,7 @@ export function polar<T extends Vector2 | Vector3>(v: T, an: number, dis: number
     return v;
 }
 
-export function angle(v: Vector3 | Vector2)
+export function angle(v: Vector3 | Vector2): number
 {
     let angle = Math.atan2(v.y, v.x);
     if (equaln(angle, 0, 1e-8)) return 0;
@@ -113,13 +113,17 @@ export function angle(v: Vector3 | Vector2)
  * @param {Vector3} [ref] 参考向量,如果为世界坐标系则为0,0,1
  * @returns
  */
-export function angleTo(v1: Vector3, v2: Vector3, ref: Vector3 = new Vector3(0, 0, 1))
+export function angleTo(v1: Vector3, v2: Vector3, ref: Vector3 = ZAxis): number
 {
-    if (!ref.equals(new Vector3(0, 0, 1)))
+    if (v1.equals(ZeroVec) || v2.equals(ZeroVec))
+        return 0;
+
+    v1 = v1.clone();
+    v2 = v2.clone();
+
+    if (ref !== ZAxis && !ref.equals(ZAxis))
     {
         ref = ref.clone();
-        v1 = v1.clone();
-        v2 = v2.clone();
         //任意轴坐标系. 使用相机的构造矩阵.
         ref.multiplyScalar(-1);
         let up = getLoocAtUpVec(ref);
@@ -131,10 +135,10 @@ export function angleTo(v1: Vector3, v2: Vector3, ref: Vector3 = new Vector3(0,
         v1.z = 0;
         v2.z = 0;
     }
-    if (v1.equals(ZeroVec) || v2.equals(ZeroVec))
-        return 0;
-    let cv = new Vector3().crossVectors(v1, v2).normalize();
-    return cv.z === 0 ? v1.angleTo(v2) : v1.angleTo(v2) * cv.z;
+
+    //法向量不能转成单位向量在判断，可能会导致原先z===0被转成大于0
+    let cv = new Vector3().crossVectors(v1.normalize(), v2.normalize());
+    return equaln(cv.z, 0) ? v1.angleTo(v2) : v1.angleTo(v2) * cv.z;
 }
 
 export function getLoocAtUpVec(dir: Vector3): Vector3
diff --git a/src/Production/Product.ts b/src/Production/Product.ts
index a5a7112af..5d794d9ab 100644
--- a/src/Production/Product.ts
+++ b/src/Production/Product.ts
@@ -791,6 +791,9 @@ export namespace Production
                 if (Math.max(z0, 0) < Math.min(z1, br.Thickness) - 1e-6 && outline.PtInCurve(p))
                 {
                     let depth = z0 < 1e-2 ? z1 : br.Thickness - z0;
+                    let angle = angleTo(XAxis, x);
+                    if (equaln(angle, Math.PI))
+                        angle = 0;
                     if (depth > 1e-2)
                         data.frontBackHoles.push({
                             type: d.isThrough ? GangDrillType.TK : GangDrillType.Ymj,
@@ -798,7 +801,7 @@ export namespace Production
                             radius: cir.Radius,
                             depth,
                             face: z0 < 1e-6 ? DrillingFace.Back : DrillingFace.Front,
-                            angle: angleTo(XAxis, x),
+                            angle: angle,
                         });
                 }
             }