The invention provides a hydraulic automatic leveling system suitable for multiple vehicles and a leveling method. The hydraulic automatic leveling system suitable for the multiple vehicles comprisesa compartment base, a bottom plate, four electric hydraulic cylinders, a wifi relay, a controller and a smartphone; four mounting grooves with upward openings are formed in the compartment base; the four hydraulic cylinders are correspondingly fixed in the four mounting grooves; hydraulic rods are connected to the upper ends of the hydraulic cylinders; the top ends of the hydraulic rods are fixedly connected with the lower surface of the bottom plate; multiple vertical buffering springs are arranged on the upper surface of the bottom plate; and load bearing plates are connected to the upper ends of the multiple vertical buffering springs. Through adoption of the wifi relay, the external smartphone is connected with the leveling system, a gravity sensor in the smartphone is adopted to measure the inclination, and a measured result is transmitted to the wifi relay so as to control the balance of a load bearing platform; and through adoption of the arrangement, an inclination angle sensorcan be eliminated, the equipment cost can be reduced, the structure is compact, the use is convenient, and the price is low.