In this paper, a center-of-mass (CoM) following system is proposed for the ground microgravity test of space bio-inspired climbing robot to solve the problem of robot attitude deflection due to the fixed suspension point in the traditional suspension method. The system of CoM following Device consists of three parts: firstly, the three-axis sliding table module actively adjusts the XY plane position of the suspension point and the z-axis gravity compensation (stroke 310/210/60 mm); secondly, the passive attitude follower structure (carbon fiber tube and gimbal/ball hinge) is designed based on the principle of parallel suspension frame, so that the suspension point can track the robot CoM in real time, and the tilting moment is eliminated; thirdly, a fuzzy-PID based control algorithm realizes Z-axis gravity compensation and X/Y-axis CoM following, where trajectory planning is allocated to the upper-level computer and motor synchronization via CAN bus is executed by the lower-level computer. The simulation analyzes the range of CoM motion of the robot climbing in 1-3-2-4 gait, and the experiment shows that the maximum following error of each axis is less than or equal to 0.92 mm, and the average following error is less than or equal to 0.18 mm. This system provides a high-precision and low-interference solution for the ground microgravity test of the space robot.