Double-gas-path pneumatic chuck

The invention discloses a double-gas-path pneumatic chuck which comprises a main body, a piston, a sliding block and a convex key. A front cavity and a rear cavity are formed in the main body, the front cavity is communicated with the rear cavity, an open groove is formed in the side wall of the front cavity, the rear cavity is provided with a first air inlet hole and a second air inlet hole, the first air inlet hole is communicated with the rear end of the rear cavity and the outside, and the second air inlet hole is communicated with the front end of the rear cavity and the outside. The piston is arranged in the rear cavity in a front-back movable mode, a sealing structure is arranged on the outer side wall of the piston, and the first air inlet hole and the second air inlet hole are separated through the sealing structure. The sliding block is connected to the front end of the piston, the sliding block is arranged in the front cavity in a front-back movable mode, an inclined face is arranged on the outer s