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 . <EOS>