Automatic cap screwing machine

The utility model relates to the technical field of bottle body packaging equipment, solves the problem that after a rotating piece makes contact with a bottle cap, the position of the bottle cap on a bottle body is easily changed, and discloses an automatic cap screwing machine which comprises a frame body, a conveying device and two cap screwing devices. The cap screwing device comprises a seat body, a first driving part, a second driving part and a plurality of rotating parts, the seat body is in sliding connection with the mounting seat, the first driving part drives the rotating parts to rotate, and the second driving part drives the seat body to slide; the cap screwing device further comprises a positioning assembly, and the positioning assembly is arranged on the base. In the process that the two second driving pieces drive the rotating pieces to move oppositely, after the two positioning assemblies position the bottle cap on the bottle body, the multiple rotating pieces make contact with the outer sid