Polydactyly is divided into seven types: type I is polydactyly of the terminal segment, type II is polydactyly of all the terminal segment, type III is polydactyly of the proximal segment, type IV is polydactyly of all the proximal segment, type V is polydactyly of the metacarpal segment, type VI is polydactyly of all the metacarpals, and type VII is polydactyly of all the phalanges. For type Ⅰ and type Ⅱ polydactyly of thumb, the surgical steps are as follows: using wedge resection on both sides of the center, that is, after making wedge resection of nail, finger belly and finger bone in the center of polydactyly, the soft tissues of finger bones and nails are combined into one finger. If the nail of one of the two fingers is larger, remove the small nail of the polydactyly, retain the repair of the lateral soft tissue and retain the lateral aspect of the thumb, and if the phalanges are deviated, wedge osteotomy is feasible to correct them. The following points should be noted for type III and IV polydactyly: the age of surgical correction is more than 3 years old, and too early correction may cause deviation due to destruction of the epiphysis and affect the movement of the joint, lateral instability and small finger ends. The following points should be noted in the surgical operation: cut the skin subcutaneously and remove the excess bones respectively, preserve the lateral collateral ligaments, tendons and some skin tissues, use the preserved lateral collateral ligaments and tendons to repair and stabilize the joint and prevent subsequent deviation, design the skin incision on the dorsal side as far as possible, and fix it with a keratocycloid pin for 6-8 weeks after surgery.