Small crane frame for building construction

The invention belongs to the technical field of building construction, and discloses a small crane frame for building construction, which comprises a bearing frame and a winch, the bottom end of the bearing frame is provided with a rotating assembly, the bottom end of the rotating assembly is fixedly provided with a moving seat, and the top end of the moving seat is fixedly connected with an air pressure cylinder; an inner cavity of the air pressure cylinder is movably sleeved with an air pressure plate, the top end of the air pressure plate is fixedly connected with a bearing rod, a connecting pipe is fixedly installed at the bottom of the air pressure cylinder, the top end of the connecting pipe is fixedly connected with a first piston cylinder, and an inner cavity of the first piston cylinder is movably sleeved with a first piston head. The top end of the first piston head is fixedly connected with a first piston rod, and the top end of the first piston cylinder is fixedly connected with a second piston cy