The invention discloses a coal gas leakage prevention automatic resetting device. The coal gas leakage prevention automatic resetting device is characterized in that a bypass pipeline is arranged on aleakage prevention device, the bypass pipeline is connected with one end of an electromagnetic valve, the other end of the electromagnetic valve is connected with an energy storage tank, a floater isarranged in a tank body in the energy storage tank, the floater is connected with an exhaust pressure regulating device, an exhaust sealing cap is arranged on the upper portion of the energy storagetank, the exhaust sealing cap is movably connected with the exhaust pressure regulating device, an exhaust pipeline is arranged at the upper end of the energy storage tank, an exhaust valve is installed on the exhaust pipeline, and a proximity switch is installed above a leakage prevention device indicating rod of the leakage prevention device. According to the coal gas leakage prevention automatic resetting device, the electromagnetic valve is installed between the leakage prevention device and the energy storage tank, the proximity switch is installed above the leakage prevention device indicating rod, a time relay is used for controlling the electromagnetic valve, automatic resetting of the leakage prevention device is realized by clearing trapped gas in a cavity, the failure problem, which besets the site for a long time and is caused by the trapped gas in the cavity, of the leakage prevention device, is fundamentally solved, and normal and safe running of coal gas water draining is ensured.