Pneumatic slip type lift sub chuck

The utility model discloses a pneumatic slip type lift sub chuck which comprises a body and a slip arranged in the body. Each insert plate groove of the slip is provided with two bearing faces from the top end to the lower portion of a slip body, the two bearing faces are located in the middle position and at the lower portion of each insert plate groove, bosses connected with a drilling platform are arranged on the body, slip inserts are installed in the insert plate grooves of the slip body, the centers of the insert plate grooves and the outer conical face of the slip body are designed into an eccentric structure, and a gap is formed between the outer conical face of the slip body and the inner conical face of the body. According to the pneumatic slip type lift sub chuck, when a large-tonnage load is borne, the bottoms of the insert plate grooves are not prone to deformation, large torque can be borne, and the slip can be lifted easily; a stroke switch is arranged in the body, when the slip body is lowered and makes contact with a contact of the stroke switch, the holding force of the slip is enlarged, and the slip can clamp a tubular column firmer.