Proposes an on-orbit non-uniformity correction method for complex scenes, in order to achieve high-frequency and highprecision relative radiation calibration for mechanically interleaved stitching time delay integration charge coupled device ( TDICCD) cameras on orbit. This method performs orthogonal secondary imaging before and after the camera rotates around the yaw axis, and uses the side slither imaging data and conventional imaging data to respectively calibrate the probe elements within and between arrays. Combining the characteristics of the wide radiation dynamic range of complex scenes, the method of multi-point curve fitting is used to calculate relative calibration parameters and finally achieve the purpose of non-uniformity correction. By using simulation imaging data to perform relative radiometric calibration experiments on uniform scenes and complex scenes, these results show that the image non-uniformity NU coefficient which is processed by the orthogonal secondary imaging calibration of the complex scene(OSICCS) in the non-uniform scene is 0. 499 1% lower than that after the common calibration method, meanwhile, the noticeable striping artifact and residual noise are removed effectively.