Abstract: In the process of coal mining, due to the existence of pin shaft clearance, the hydraulic support will incline laterally, which seriously threatens the stable operation and support state of the hydraulic support. Based on the analysis of pin shaft connection structure, this paper presents a virtual simulation method of hydraulic support motion based on pin shaft clearance. Firstly, the pin shaft connection structure of hydraulic support is analyzed from three aspects of single pin shaft connection, double pin shaft connection and multi pin shaft space constraint, and the multi pin shaft constraint model of hydraulic support is established. Then, the physical components are added to the virtual model of hydraulic support through Unity3D, and the simulation of hydraulic support based on gravity and physical collision is realized under different pin shaft clearance. hirdly, from the influence of seven factors on the lateral stability of the support, such as the pin axis of the rear link and the pin axis of the front link, the orthogonal experimental analysis of the simulation model with seven factors and three levels is carried out, and the experimental verification is carried out on the hydraulic support prototype system. The experimental results show that the changes of the simulation parameters are basically consistent with the changes of the actual hydraulic support motion parameters. The influence of connecting pin between column and base on the lateral stability of hydraulic support is the largest, and that of connecting pin between connecting rod and base is the smallest. This method provides a reference and application practice for solving and monitoring the attitude of hydraulic support under different pin shaft clearances.