Abstract: This study aims to research submarine motion control features in different conditions and com-plex environments in order to solve the problem of actual submarine control and apply it to building an actu-al hydraulic control platform. The paper focuses on the vertical motion of submarines, designs a fast termi-nal sliding mode control algorithm and analyzes the data using the combined simulation and experiment method to study the robustness and reliability of a submarine's vertical motion control system for hydraulic and control. At the same time, the simulation and experiment results analyze the hysteresis and oscillation of the hydraulic steering gear, and effectively reduce the chattering that may be caused by sliding mode variable structure control. This system can be used in simulations to solve the problems of new submarine control characteristics.