Automatic water replenishing device of explosion-proof water shed for coal mine

The automatic water replenishing device comprises a water replenishing pipe and a water inlet pipe, the water replenishing pipe and the water inlet pipe are in threaded sealing connection, a through water replenishing hole is formed in the top of the water replenishing pipe, a sealing area is formed in the middle bottom of the water replenishing pipe, a movable plug tightly attached to the inner wall is arranged in the sealing area, and the movable plug is connected with the water replenishing pipe. The bottom of the movable plug is connected with a floating plate through a connecting rod, through holes communicating with the sealing area are symmetrically formed in the outer wall of the water supplementing pipe, clamping pieces used for fixing the movable plug are arranged in the through holes, and the outer wall of the water supplementing pipe is movably sleeved with an extrusion ring driven by two electric push rods; water outlet holes are formed in the two sides of the top of the movable plug. According t