Aimed at the problem of poor lifting stability of the existing pitching stereo garage, the CATIA software was used to improve the structure of the pitching stereo garage. In order to compare and analyze the stability of the pitching stereo garage before and after improvement, two kinds of pitching stereo garage three-dimensional models were imported into ADAMS for motion simulation. The results show that the improved pitching stereo garage system is more stable.The structural optimization was carried out with the minimum standard deviation of the driving force fluctuation of the garage hydraulic cylinder after improvement.It is found that the driving force fluctuation of the optimized pitching stereo garage is greatly reduced，the lifting stability of stereo garage is improved, which provides a reference for its mechanical structure design.