The invention discloses a gun head assembly and electricity charging gun, the gun head assembly includes a shell, a gun head back cap installed on the gun head shell and provided with a through hole, and a terminal bushing used for securing a first terminal passing through the through hole and entering the gun head shell. The technical scheme can after the terminal is pressed fit for the cable and inserted into the gun head shell, perform gun assembly, the technical scheme operates simple, greatly lowers the rejection rate in the assembling process, evidently increases the efficiency of assembling, and causes no damage to the outside surface of the head gun shell. Meanwhile, if the gun head gets brittle and cracked and is in need of replacing, only the shell of the gun head needs to be replaced, avoiding a second terminal crimping to the cable, the assembly requires less time and labor, operates simple, does not have to be returned to the factory for repair, the user alone can complete the replacement of the gun head shell, can readily to be replaced and used, greatly lowers the cost of post manufacturing maintenance.