双叶皮瓣是一种特殊形式的皮瓣，通过对双叶皮瓣设计中的数学原理的探讨，找出双叶皮瓣各部分及与原发缺损间的数量关系，为临床应用设计提供理论依据。结论：（１）双叶皮瓣的设计中心与旋转轴心是两个点，两点间的最大距离等于缺损半径；（２）双叶皮瓣与缺损长轴间设计夹角与皮瓣实际旋转角度不一致，理论上当设计夹角为９０°时，皮瓣最小旋转角度是６０° Bilobal flap is a special form of flap. Through the discussion of the mathematical principle in the design of bilobal flap, the relationship between the various parts of the bilobal flap and the primary defect is found, which is provided for clinical application design Theoretical basis. Conclusions: (1) The design center of the double-leaf flap and the rotation axis are two points, the maximum distance between the two points is equal to the defect radius; (2) the design angle between the double- Rotation angle is inconsistent, in theory, when the design angle of 90 °, the minimum flap rotation angle is 60 °