Abstract: With the rapid development of aerospace technology, as the near neighbor of the Earth, the Mars has become the main research target of the leading space power in the world. To complete the Mars patrolling area topography and geological exploration missions, true color images with high resolution obtained by multispectral cameras can be used directly as observations. In order to find the landing point, the Mars multispectral camera should possess the mapping function with precise positions, so it is necessary to conduct the geometric calibration for measuring intrinsic elements. The Zhang Zhengyou calibration algorithm is used to provide initial values, and then combined with the improved Heikkilä algorithm in this paper. After analyzing the uncertainty of the calibration results, and finding out the source of experimental errors, an improved method for calibration parameters is proposed to meet the requiremens, which lays a solid foundation for 3D reconstruction and other fields of computer vision.