Automatic water draining device

The utility model relates to a water draining device for a coal mine water sump, particularly to an automatic water draining device, and solves the problems of time wasting, labor wasting and low production efficiency of the traditional manual water draining device under long coal mine working line. The automatic water draining device comprises a steel plate which is fixed on the water sump and is vertically arranged; connecting angular steel is fixed to both the left side and the right side of the steel plate; steel pipes are fixed on both the connecting angular steel; steel bars penetrate through the steel pipes; a dual-button switch which contacts the steel bars and is fixed on the steel plate is arranged at the upper end of each of the steel bars; an inner tube is fixed at the lower end of one steel bar; a plumb bob is connected with the lower end of the other steel bar; a fixed pulley is arranged on the steel plate; and a nylon rope which is connected with the plumb bob and the inner tube and moves round