A brush head assembly, comprising a brush head body, a linking component and a locking cylinder; the front end of the brush head body is provided with bristles, and the rear end is provided with a component assembly cavity; the linking component comprises a base and a component main body, a shaft center hole is arranged at the shaft center of the base and the component main body, and the shaft center hole is used for insertion of a drive shaft; the component main body is installed in the component assembly cavity, and a lock cylinder assembly cavity is formed between the component main body and an inner wall of the component assembly cavity, wherein the lock cylinder assembly cavity is communicated with the shaft center hole; characterized in that: the locking cylinder is a deformable elastic piece, comprising a fulcrum force-receiving part at the middle part and a force applying part at both ends for applying elastic force; the connecting line connecting a first force applying part with the fulcrum force-receiving part and the fulcrum force-receiving part with a second force applying part is V-shaped; and the locking cylinder is embedded in the lock cylinder assembly cavity, so that when the drive shaft is inserted into the shaft center hole, the locking cylinder is elastically deformed to generate elastic force to lock the drive shaft through the two force applying parts. the front end of the brush head body is provided with bristles, and the rear end is provided with a component assembly cavity; the linking component comprises a base and a component main body, a shaft center hole is arranged at the shaft center of the base and the component main body, and the shaft center hole is used for insertion of a drive shaft; the component main body is installed in the component assembly cavity, and a lock cylinder assembly cavity is formed between the component main body and an inner wall of the component assembly cavity, wherein the lock cylinder assembly cavity is communicated with the shaft center hole; characterized in that: the locking cylinder is a deformable elastic piece, comprising a fulcrum force-receiving part at the middle part and a force applying part at both ends for applying elastic force; the connecting line connecting a first force applying part with the fulcrum force-receiving part and the fulcrum force-receiving part with a second force applying part is V-shaped; and the locking cylinder is embedded in the lock cylinder assembly cavity, so that when the drive shaft is inserted into the shaft center hole, the locking cylinder is elastically deformed to generate elastic force to lock the drive shaft through the two force applying parts. the locking cylinder is a deformable elastic piece, comprising a fulcrum force-receiving part at the middle part and a force applying part at both ends for applying elastic force; the connecting line connecting a first force applying part with the fulcrum force-receiving part and the fulcrum force-receiving part with a second force applying part is V-shaped; and the locking cylinder is embedded in the lock cylinder assembly cavity, so that when the drive shaft is inserted into the shaft center hole, the locking cylinder is elastically deformed to generate elastic force to lock the drive shaft through the two force applying parts.