Aiming at electro-hydraulic proportional leveling system of large aerial work platform, the model of the system is established and the stability is validated. Because the parameters of traditional PID can be used one state only, the leveling performance of large aerial work platform changes with the change of radius-changing velocity. Fuzzy logic is used to PID control, whose parameters can be adjusted automatically according to error and error changing. A comparison analysis between PID and Fuzzy PID is carried with the help of AMESim/Simulink. The simulation results show that the fuzzy PID has better effects and robustness.