An automatic leveling control system is added to the self-developed leveling mechanism of mountain tractor. The system takes the programmable logic controller(PLC) as the main control core, the inclination sensor as the inclination detection mechanism of the body platform, and the fuzzy PID as the leveling control algorithm. By monitoring the angle value detected by the inclination sensor, the rotation of the servo motor and the expansion of the servo cylinder are adjusted in real time to realize the automatic leveling of the body platform. The static test results show that when the tractor body platform is inclined by 15°, it takes 1.851 s and 1.882 s to complete the lateral and longitudinal leveling respectively, and the leveling is completed within 3.319 s. The dynamic test results show that the tractor has a running speed of 1.73 km/h and a maximum slope of 15°. It takes 6.253 s and 6.853 s to complete the horizontal and vertical leveling of the vehicle body platform respectively, and the maximum overshoot angles are 9.053 3°and 8.687 2° respectively. The angle deviation of the vehicle platform after leveling is finally controlled within ±0.5°.