Abstract: To address the challenge of multi-sensor data transformation and synthesis in ground-based micro-vibration testing of large space payloads, an algorithm for micro-vibration data processing was proposed based on the testing of the coronagraph payload of the Chinese Space Station Telescope (CSST). The algorithm used a simple coordinate transformation to convert multi-sensor measurement data at the interface between the coronagraph payload and the satellite from the sensor's local coordinate systems to a common reference frame. Utilizing the transformed sensor data as input, the algorithm then applied spatial force synthesis theory to calculate the six-component force and moment (F_x, F_y, F_z, M_x, M_y, M_z) at the payload’s center of mass. To verify the effectiveness of the spatial force synthesis theory used in the algorithm, a simplified force measurement platform with four sensors was constructed and compared with a calibrated force measurement platform, both measuring the same vibration source. The results show that the relative root-mean-square (RMS) error of the three-axis forces is within 4%, and the RMS error of the three-axis moments is within 8%. This algorithm can be used for data processing in micro-vibration testing of large space payloads and serves as a tool for guiding and validating micro-vibration isolation design.