The invention discloses a waterproof electric cabinet which comprises a power distribution cabinet body and a waterproof cover. Positioning blocks are fixedly mounted at the left side and the right side of the inner wall of the power distribution cabinet body, fixing mechanisms are fixedly mounted in the two positioning blocks correspondingly, and circular containing grooves are formed at the opposite ends of the two positioning blocks correspondingly. Clamping mechanisms are fixedly mounted in the two circular containing grooves correspondingly, positioning grooves are formed at the left sideand the right side of the waterproof cover correspondingly, and the two positioning grooves are slidably connected with the positioning blocks correspondingly. According to the cooperative use of thepower distribution cabinet body, the waterproof cover, the positioning blocks, a fixing mechanism, a square placement groove, an extrusion spring, a square convex block, a circular placement groove,the clamping mechanisms, a pneumatic cylinder, a piston, an extrusion rod, a limiting block, a circular clamping block, a positioning groove, a square groove, a circular clamping groove, a stop block,a sliding groove and a sliding block, the problem that the waterproof effect of an existing power distribution cabinet is not good, is solved, and the waterproof electric cabinet has the better waterproof effect.