Aiming at the control process of two-dimensional motion platform, this paper proposes a variable synchronization ratio circular interpolation method, specifically targeting the issue of large circular interpolation errors caused by the asynchronous motion of two physical axes. The proposed method uses the relationship between the change of interpolation point coordinates and the angle of the center of the circle. A virtual axis is constructed with the corresponding angle of the circle center at each interpolation point serving as the output. This virtual axis acts as the guide axis of synchronous motion, while the physical axes serves as the follower axes, establishing the synchronous motion relationship between the virtual axis and the physical axes. Based on the positional relationship between the guide axis and the follower axes, the synchronization ratio is obtained using the center angle as the intermediate parameter. The circular interpolation process is then transformed into the calculation of the synchronization ratio for each interpolation cycle. By adjusting the synchronization ratio during each interpolation cycle, the synthetic direction of the physical axes is changed, enabling precise circular interpolation. Experimental results show that the proposed method can control the two-dimensional motion platform to achieve circular interpolation at a relatively smooth speed. This not only improves the efficiency of the circular interpolation but also achieves high accuracy, making it highly suitable for applications requiring precise motion control. Keywords:two-dimensional motion platform; circular interpolation; synchronous motion; synchronizati