Taking two neighboring scenes SPOT5 satellite data of the Liupanshui City of Guizhou Province, based onthe scale of 1∶10 000 DRG as ground control points of reference and different scales accuracy of the DEM for theimages ortho-rectification which compared test, it was analyzed in detail the effect of incidence angle and differentscales accuracy of the DEM for the accuracy of the results of SPOT5 ortho-image. On the analysis, itwas found thatthe incidence angle was an important factor leading to the“layover”in SPOT5 ortho-image. It will provide theimportant basis for the next step of eliminating this phenomenon.