In this paper, the conceptual design with integrating motion control and considering the cross current was applied to establish a submarine motion simulator, where the path motion stability is evaluated. The methods used to construct the simulator include the standard navigation approach by applying the LOS algorithms and PD control Euler-Rodriguez quaternion for conversion between submarines motion and flow coordinates, and the fourth-order Runge-Kutta method for solving the system of simultaneous motion equations. Finally, the simulator was applied for testing the motion performance of a 3000-ton submarine by using fixed-points autopilot test for determining path motion stability and turning test for determining the course-change ability. The results show that the motion of the submarine in the horizontal plane can achieve the path stability and also reasonable course-change ability.