The performance of hydraulic turnover mechanism of heavy truck cab is an important part to measure the vehicle performance.In order to improve the performance of the turnover mechanism,the mathematical model of the turnover mechanism was established,and the push-out force coefficient,oil pressure fluctuation coefficient and flipping capacity were taken as the performance evaluation indexes of the turnover mechanism,and the performance optimization problem of the turnover mechanism was transformed into a constrained multi-objective optimization problem.According to the evaluation function of linear weighting method,the constrained multi-objective problem was optimized and the analytic hierarchy process (AHP) was used to determine the weighted coefficients of each performance evaluation index,finally the optimization results were solved after setting the constraint conditions.For a certain type of heavy truck cab turnover mechanism optimization analysis,the system model was optimized and solved in MATLAB,and the AMESim model was built for simulation verification.The results show that the analytic hierarchy process (AHP) is a stable and effective way to determine the weighting coefficient,and the optimization analysis results show that the performance of the turnover mechanism is improved by 11.72% compared with that of before optimization，which is approximate to the simulation results.