The invention provides an opening and closing device for avoiding overshooting of a vacuum cavity door and a vacuum cavity. The opening and closing device comprises a linear driving part with a linear driving shaft, a joint part, a baffle sleeve, a baffle, a bolt pin and a baffle blocking part, wherein one end of the joint part is fixed to the edge of the cavity door, and the other end of the joint part is provided with a connecting hole; one end of the linear driving part is movably connected to the outer wall of the vacuum cavity, and the other end of the linear driving part is movably connected with the other end of the joint part through the connecting hole; the cavity door is opened or closed through the rotation of the joint part driven by the rotation of the linear driving part; the baffle sleeve surrounds one end of the linear driving shaft; the baffle is located in the connecting hole of the joint part, and provided with a stop end close to the linear driving part; the bolt pin penetrates through the connecting hole, the baffle is fixedly connected with the baffle sleeve through the connecting hole, and the baffle is movably connected with the joint part through the connecting hole; and the baffle blocking part located on the joint part is arranged close to the stop end of the baffle, and when the stop end of the baffle makes contact with the baffle blocking part, the joint part is stuck by the baffle and cannot rotate continuously.