Automatic water level controller through the automatic adjustment control, when the water level is lower than a water outlet, automatic water supply; water level is higher than the water outlet to stop water supply, no need of power supply. According to the mechanical air water container water level always maintained at a certain level, can effectively avoid the pigs, cattle and sheep caused by sewage water. In the material relative to the traditional water dispenser skin pad is easy to aging, the water level controller using the pressure and the principle of water pressure automatic control of the water tank without wearing parts .