Automatic flood discharge device

The utility model discloses an automatic flood discharge device. The automatic flood discharge device comprises a siphon which comprises a water inlet pipe, a dam crest pipe and a pumping pipe, a water pump and a second check valve are arranged on a water suction pipe which is in parallel connection with the water inlet pipe, and a first check valve is arranged on the water inlet pipe. The automatic flood discharge device further comprises a liquid indicator and a water pump driving power source, the liquid indicator is arranged on a dam and connected with a waveform transformation module which is respectively connected with a control end of a relay and a control end of a time controller, and the water pump driving power source is connected with the water pump sequentially through the relay and the time controller. The automatic flood discharge device is simple in structure and convenient to use; automatic flood discharge of small dams can be realized; by means of siphon type drainage, energy is saved, idling of the water pump after drainage is completed is avoided, and accordingly loss of the water pump is reduced.