A water level automatic control system of a landslide physical model test comprises water tanks, a control cabinet and a slope surface information acquisition device. Two water tanks are respectively arranged at the front and at the back of a landslide physical model test frame. Side faces of the two water tanks, which are contacted with a landslide model, are respectively provided with a plurality of groups of water feeding and discharging holes. Bottoms of the water tanks are connected with water inlet pipelines and water outlet pipelines respectively, water pumps and water inlet electromagnetic valves are arranged on the water inlet pipelines, and water outlet electromagnetic valves are arranged on the water outlet pipelines. Liquid level transmitters for monitoring water levels in the water tanks are arranged in two water tanks, the control cabinet is respectively connected with all the liquid level transmitters, the water pumps, the water inlet electromagnetic valves and the water outlet valves and used for receiving water level signals and controlling opening and closing of the water pumps and the electromagnetic valves, and the slope surface information acquisition device is arranged above the water tank arranged at the front of the landslide physical model test frame. The water level automatic control system of the landslide physical model test can monitor parameters of landslide surface displacement and the like under the condition of stored water level variation precisely and comprehensively and provide an important basis for landslide stability studies.