Air-proof cassette

The air-proof cassette comprises a box body, the box body is composed of a bottom plate and side plates arranged on the side walls of the bottom plate in a surrounding mode, a long screw is installed on the top of the box body, and a lock catch is arranged on the long screw in a sleeved mode. According to the anti-gas cassette, the anti-falling limiting part is arranged on the long screw, the anti-falling limiting part can prevent the long screw from being pulled out of the elliptical hole, the long screw is sleeved with the lock catch, the long screw is matched with the inclined part on the box body, and when the long screw is rotated, the thread direction of the thread part of the long screw is consistent with the thread direction of the mounting hole of the lock catch; therefore, the lock catch can be driven to move upwards along the inclined part, the saw-shaped teeth of the lock catch stretch out towards the outer side of the box body, the protruding block can limit the lock catch to prevent the lock cat