The omnidirectional motion platform system was a 2D motion platform that could realize walking of the human body in various directions. In order to realize the motion control of the human body in the omnidirectional motion platform, the firstorder control algorithm added to the observer to explore the motion control of the platform was used. Firstly, the algorithm was simulated by MATLAB software to verify the feasibility of the method. Then, the effectiveness of the control algorithm was verified by field tests. Experiments showed that the firstorder control algorithm added to the observer achieved effective motion control for the omnidirectional motion platform. The exploration of this motion control strategy provided a feasible control idea and solution for motion control of the omnidirectional motion platforms.