Aiming at the calibration of camera with a narrow field of view for deep space, the simulation analysis method based on stereo target is built. The spatial distribution influence of the target points on the accuracy of camera calibration is analyzed thoroughly. The number and position distribution of the target points are reasonably designed before camera calibration. The results show that spatial distribution scope of the target points has the greatest influence on the calibration accuracy while the number of target points has little influence. The calibration accuracy can be enhanced by arranging target points from the nearest measuring distance. A center location algorithm combining the region of interest with sub-pixel edge detection by the gray moment is proposed to locate the image target spot. The location accuracy and the processing efficiency of the image algorithm are improved effectively. The virtual stereo target is arranged to calibrate the intrinsic parameter of a camera quickly. The calibration precision is high and the method has practical application value. This method is also applicable to camera calibration without target stitching.