Self-locking mechanism and box body assembly

The utility model relates to a self-locking mechanism and a box body assembly. Wherein the self-locking mechanism comprises a lock seat, a lock tongue, an elastic piece and a control part; the lock tongue and the control part are both arranged on the lock seat, the lock tongue can move relative to the lock seat in the first direction, and the control part can slide relative to the lock seat in the second direction; the control part is connected with the spring bolt, the contact part, connected with the spring bolt, of the control part is an inclined surface and/or the contact part, connected with the control part, of the spring bolt is an inclined surface, and the inclined surface is inclined relative to a first direction; when the control part slides in the second direction, the contact part, connected with the spring bolt, of the control part acts on the spring bolt, so that the spring bolt moves into the lock hole in the first direction; the elastic piece is connected between the spring bolt and the lock s