Abstract: In view of the image particularity of stereo camera onboard Chang'E-1 orbitor, the projection method was selected to complete the lunar nadir images mosaic of Apollo 12, Apollo 14 and Apollo 15 landing sites. Based on analyzing cylindrical projection, the coordinate formulae of lunar shearing 35º Mercator projection were obtained. Firstly, the latitudes, longitudes and DN values were read and written to files. A blank frame was established using the four vertices' latitudes and longitudes. Then grids were divided in vertical and horizontal directions, according to the resolution, length ratio and projection theory, realizing the frame's pixels. The DN mosaic was completed along with the coordinates matching, and the matching errors were controlled in less than one pixel. At the same time, the DN values were smoothed for the overlapped regions. Finally the DN values were restored to image, which was the mosaic image. The method has widespread use, and it can also be used for other tracks images mosaic.