diff --git a/__test__/Geometry/__snapshots__/intersect.test.ts.snap b/__test__/Geometry/__snapshots__/intersect.test.ts.snap
index 3993a2672..39c1d7a14 100644
--- a/__test__/Geometry/__snapshots__/intersect.test.ts.snap
+++ b/__test__/Geometry/__snapshots__/intersect.test.ts.snap
@@ -140,9 +140,9 @@ Vector3 {
 
 exports[`三维空间直线相交测试 2`] = `
 Vector3 {
-  "x": 4.75,
-  "y": 4.75,
-  "z": 4.75,
+  "x": 1.5,
+  "y": 1.5,
+  "z": 1.5,
 }
 `;
 
@@ -164,7 +164,7 @@ Vector3 {
 
 exports[`相交测试 2`] = `
 Vector3 {
-  "x": 2.5,
+  "x": 3,
   "y": 0,
   "z": 0,
 }
diff --git a/src/GraphicsSystem/IntersectWith.ts b/src/GraphicsSystem/IntersectWith.ts
index fb28a0b60..8c74f4c10 100644
--- a/src/GraphicsSystem/IntersectWith.ts
+++ b/src/GraphicsSystem/IntersectWith.ts
@@ -237,16 +237,38 @@ export function IntersectLAndLFor3D(p1: Vector3, p2: Vector3, p3: Vector3, p4: V
 
     let v1 = p2.clone().sub(p1).normalize();
     let v2 = p4.clone().sub(p3).normalize();
-    let w = p3.clone().sub(p1);
-    if (Math.abs(v1.dot(v2)) === 1)
+    let w = p3.clone().sub(p1).normalize();
+
+    if (equaln(Math.abs(v1.dot(v2)), 1) && equaln(Math.abs(v1.dot(w)), 1)) //平行共线
     {
-        let tmpLine = new Line(p1, p2);
-        let par = tmpLine.GetParamAtPoint(p3);
-        if (par)
+        const selectPt = (line: Line, p1: Vector3, p2: Vector3) =>
         {
-            //FIXME:这样拿交点会导致判断点在线上发生错误
-            pt = midPoint(midPoint(p1, p2), midPoint(p3, p4));
+            let tmpP: Vector3;
+            if (line.PtOnCurve(p1))
+            {
+                tmpP = p1;
+            } else if (line.PtOnCurve(p2))
+                tmpP = p2;
+            else
+            {
+                let dist1 = line.EndPoint.distanceToSquared(p1);
+                let dist2 = line.EndPoint.distanceToSquared(p2);
+                tmpP = dist1 > dist2 ? p1 : p2;
+            }
+            return tmpP;
         }
+
+        let tmpLine = new Line(p1, p2);
+        let tmpLine2 = new Line(p3, p4);
+
+        let tmpP1 = selectPt(tmpLine, p3, p4);
+        let tmpP2: Vector3 = selectPt(tmpLine2, p1, p2);
+
+        pt = midPoint(tmpP1, tmpP2);
+
+    } else if (Math.abs(v1.dot(v2)) === 1) //平行不共线
+    {
+        return undefined;
     }
     else if (equaln(getDeterminantFor3V(v1, v2, w), 0, 0.01))
     {
diff --git a/src/GraphicsSystem/OffestPolyline.ts b/src/GraphicsSystem/OffestPolyline.ts
index 0ef4350de..c9d2353cb 100644
--- a/src/GraphicsSystem/OffestPolyline.ts
+++ b/src/GraphicsSystem/OffestPolyline.ts
@@ -1055,12 +1055,13 @@ export class PolyOffestUtil3
 {
     private m_Polyline: Polyline;
     private m_OffestDist: number;
-    offDir: number;
+    private m_OffDir: number;
+    private IsKeepAllCurves = false;
     constructor(pl: Polyline, offest: number)
     {
         this.m_Polyline = pl;
         this.m_OffestDist = offest;
-        this.offDir = Math.sign(this.m_OffestDist) * Math.sign(this.m_Polyline.Area2);
+        this.m_OffDir = Math.sign(this.m_OffestDist) * Math.sign(this.m_Polyline.Area2);
     }
     //偏移
     GetOffsetCurves(): Curve[]
@@ -1083,12 +1084,18 @@ export class PolyOffestUtil3
         let cus = this.trimByContours(newPls, contours);
 
         // return cus;
-        if (this.m_Polyline.IsClose && this.offDir < 0)
+        if (this.m_Polyline.IsClose && this.m_OffDir < 0)
         {
             cus = cus.filter(pl => isTargetCurInSourceCur(this.m_Polyline, pl))
         }
 
-        return this.linkSelfingCurves(cus);
+        if (this.IsKeepAllCurves)
+        {
+            return this.linkSelfingCurves(cus);
+        } else
+        {
+            return this.linkSelfingCurves(cus);
+        }
 
     }
     //偏移曲线
@@ -1286,6 +1293,7 @@ export class PolyOffestUtil3
                         buildArcJoinList(cir2, laterLine.StartPoint);
                     }
                 }
+                // 补完圆弧直接退出函数
                 return;
             }
         }
@@ -1427,9 +1435,9 @@ export class PolyOffestUtil3
 
                     if (equaln(parForFront, 0))
                     {
-
+                        //理论应该把该段移除出来
                     }
-                    else if (equaln(parForFront, 1))
+                    else if (equaln(parForFront, 1, 1e-6))
                     {
                         pl.Join(frontLine);
                     }
@@ -1440,7 +1448,7 @@ export class PolyOffestUtil3
                         cus.unshift(spliteCusForFront[1]);
                         j++;
                     }
-                    if (equaln(parForLater, 0))
+                    if (equaln(parForLater, 0, 1e-6))
                         frontLine = cus.splice(j, 1)[0];
                     else
                     {