The invention discloses an automatic lifting platform leveling control method and system. The method comprises the following steps: finding the shortest expansion length of a hydraulic cylinder, obtaining a proportionality coefficient, determining a tracking target length value, adjusting the expansion length of the hydraulic cylinder according to closed-loop feedback control, and enabling a floating surface and a target plane to be parallel when the expansion length of the hydraulic cylinder and the ranging length of a corresponding sensor are proportional. According to the method and systemdisclosed by the invention, excessive manual operations are not needed, the upper surface M2 of the platform can be automatically leveled to be parallel to a target plane M3, and the working efficiency of the platform is greatly improved; and the platform control precision is improved, and the personal safety of an operator is ensured.