diff --git a/src/Add-on/Fillet.ts b/src/Add-on/Fillet.ts
index b6c14e17b..49594376c 100644
--- a/src/Add-on/Fillet.ts
+++ b/src/Add-on/Fillet.ts
@@ -331,26 +331,55 @@ export class CommandFillet implements Command
         let parF1 = Math.floor(param1);
         let parF2 = Math.floor(param2);
 
-        //TODO:自交多段线倒角
         //共线
         if (parF1 === parF2)
             return;
 
-        //是否相邻。
+        let c1 = pl.GetCurveAtParam(param1);
+        let c2 = pl.GetCurveAtParam(param2);
+
+        if (equalv3(c1.GetFistDeriv(1).normalize(), c2.GetFistDeriv(0).normalize()))
+            return;
+
         let rem = parF2 - parF1;
-        if (rem === 1
-            || (rem + 1 === pl.EndParam)
+        if (rem === 1 || (rem + 1 === pl.EndParam)//是否相邻
         )
         {
         }
-        else
-            return;
+        else//自交多段线
+        {
+            if (!(c1 instanceof Line && c2 instanceof Line))
+                return;
 
-        let c1 = pl.GetCurveAtParam(param1);
-        let c2 = pl.GetCurveAtParam(param2);
+            let interPts = c1.IntersectWith(c2, IntersectOption.OnBothOperands);
+            if (interPts.length === 0)
+                return;
+
+            let ipt = interPts[0];
+            let splitParam1 = Math.floor(param1) + c1.GetParamAtPoint(ipt);
+            let splitParam2 = Math.floor(param2) + c2.GetParamAtPoint(ipt);
+
+            let cus = pl.GetSplitCurves([splitParam1, splitParam2]);
+            if (cus.length >= 2)
+            {
+                cus.splice(1, 1);
+
+                let pl1 = cus[0];
+                for (let i = 1; i < cus.length; i++)
+                    pl1.Join(cus[i]);
+
+                let es1 = new PromptEntityResult();
+                es1.Entity = pl1;
+                es1.Point = c1.GetPointAtParam(0.1);
+
+                let es2 = new PromptEntityResult();
+                es2.Entity = pl1;
+                es2.Point = c2.GetPointAtParam(0.9);
+
+                return this.FilletPolyLineSelf(es1, es2);
+            }
+        }
 
-        if (equalv3(c1.GetFistDeriv(1).normalize(), c2.GetFistDeriv(0).normalize()))
-            return;
 
         let es1 = new PromptEntityResult();
         es1.Entity = c1;