Automatic locking and unlocking device

The utility model provides an automatic locking and unlocking device, which comprises a mounting seat, a locking mechanism, a locking mechanism and an unlocking mechanism, the mounting seat is fixedly connected to a mounting surface, a rectangular cavity is upwards formed in the lower surface of the mounting seat, and a rectangular through groove in the front-back direction is formed in the lower surface of the mounting seat; the upper portion of the rotating hook is a strip-shaped body, the lower portion of the rotating hook is a hook-shaped body, the rotating hook is rotatably pivoted in the rectangular cavity of the mounting base through a fixing pin, and the position of the fixing pin is set as follows: in a non-stress state, the hook-shaped body of the rotating hook is hidden in the rectangular cavity and does not extend into the rectangular through groove; the strip-shaped body partially extends into the rectangular through groove; after the annular connecting piece extends into the rectangular through