In order to address the issues of decreased stability and susceptibility to overturning in high ground clearance crop protection machinery caused by its high center of gravity and uneven terrain, focusing on the attitude control of the vehicle body of such machinery, a high ground clearance crop protection machinery attitude control system was developed. Firstly, based on kinematic analysis theory, a kinematic model was established to relate the displacement of hydraulic cylinders to the change in inclination angle when each supporting point reached the horizontal position of the vehicle body. Secondly, a fourpoint independent control hydraulic system was designed, and key parameters were calculated to select appropriate hydraulic components. Then, mechanical-hydraulic simulations of vehicle attitude adjustment were conducted by using RecurDyn and AMESim software. Simulation results indicated that under longitudinal and transverse slope conditions, the maximum pitch angle deviation was 0.19° and the lateral angle deviation was 0.1°. When traversing a 200mm high ridge, the maximum pitch angle deviation was 0.28° and the maximum roll angle deviation was 0.17°. Finally, prototype performance tests were carried out. The test results showed that under transverse and longitudinal slope conditions, the maximum lateral angle deviation was 0.21°, and the maximum pitch angle deviation was 0.36°, with absolute adjustment angles all less than 0.5°. During ridge crossing, the pitch angle remained within ±0.5° for over 95% of the time, with minimal terrain influence. The curves of prototype test results aligned closely with those obtained from simulation analysis, validating the effectiveness of the attitude control system and providing theoretical reference for the study of agricultural machinery chassis attitude adjustment systems.