The invention provides a DEM-aided SAR image registration method with high accuracy. The technical scheme is as follows: for two SAR images obtained from the same scene, the elevation corresponding toeach pixel of the main image is calculated; then an appropriate number of pixels are selected as control points in the main image, the pixel positions of the control points in the auxiliary image areobtained by correlation coefficient method, and the azimuth registration offset and the distance registration offset between the main image and the auxiliary image at the control points can be obtained. Then a polynomial related to pixel coordinates and pixel elevation is fitted by least square fitting. Finally, the parameters of each pixel of the main image are substituted into the polynomial toobtain the azimuth and range offset between the pixel of the main image and the corresponding pixel of the auxiliary image, and the SAR image registration is completed. The invention solves the problem of low local registration accuracy of the existing SAR image two-dimensional function registration method under the condition that the long baseline is in the long baseline and the complex terrainarea.