The invention discloses a polishing head quick-detaching mechanism which is used for mounting of a polishing head. The polishing head quick-detaching mechanism comprises an output shaft which is used as power output of a polisher. According to the output shaft, polishing head periphery fixing can be achieved, the gravity center of a part for transmitting torque is changed in a jumping mode when the part rolls. The output shaft is provided with an elastic piece which protrudes out of the surface of the output shaft part where the elastic piece is placed. When the polishing head is arranged in the output shaft in a sleeved mode, the radial size of the elastic piece is under stress and is reduced. After the polishing head is arranged on the output shaft, the radial size of the elastic piece is restored to the original state. At the time, the elastic piece can limit axial separating of the polishing head. An unlocking mechanism is further included. The unlocking mechanism can have an effect on the elastic piece, so that the radial size of the elastic piece is reduced. When the polishing head is mounted, plastic deforming of the polishing head does not exist, deforming parts are all placed on the elastic piece, accordingly, the quick-detaching mechanism is low in relative loss, meanwhile, polishing head replacing is quick, and convenience and quickness are achieved.