Synchronous adjustment of the body and implement posture of hilly mountain tractors helps to improve the safety and efficiency of their operations. The current research on the attitude adjustment of hilly tractors is mainly focused on the body or implement attitude control. Its accuracy and reliability are difficult to meet the actual requirements. A synchronous control system for tractors in hilly and mountainous areas was designed based on the neural network PID algorithm. Specifically, according to the different attitude adjustment requirements of the body and implement, a corresponding attitude adjustment system was designed respectively and its dynamics was modeled. And then a synchronous control algorithm based on neural network PID was adopted. Comparisons with the conventional PID control algorithm was conducted, and simulation analysis was performed. The simulation results verified the effectiveness of the proposed neural network PID algorithm, and its control performance was better than that of the PID control algorithm. Finally, experimental verifications were carried out on fixedslope and random pavement operations. The experimental results showed that the accuracy and stability of the proposed neural network PID control method were better than those of the PID control method. On a road with a fixed slope of about 14°, the maximum error of the vehicle lateral inclination angle was 0.8640°, the maximum error of the absolute value difference of the left and right swing mechanism was 0.9600°, and the maximum error of the machine lateral inclination angle was 0.6497°; the vehicle lateral inclination was the largest on a random slope road, the error was 2.8740°, the maximum error of the absolute value of the swing angle of the left and right swing mechanism was 4.2800°, and the maximum error of the machine lateral inclination angle was 1.7620°. It can be seen that the proposed method had good control accuracy and stability, and can meet the actual needs of hilly and mountain tractors.