Landing gear retracting system is a complex system integrating mechanical, electrical and hydraulic. With the development of simulation technology, it is convenient and fast to study the performance of retracting and retracting system by computer simulation. Aiming at the present situation that the single software simulation method is difficult to realize this kind of complex system, a method combining theoretical analysis and multidisciplinary simulation technology analysis is proposed, which provides a more accurate analysis means for the landing gear retracting system. In this paper, the mechanical dynamics model of the retraction system is established according to the retraction principle of the landing gear model, and then the simulation model of the hydraulic system is established according to the hydraulic principle. On this basis, a multidisciplinary co-simulation model combining the two is completed. Finally, the results of co-simulation under various operating conditions are compared with the experimental results, and the accuracy and convenience of co-simulation technology in the analysis of landing gear retracting system are verified.