In this paper, A new mixed sub-pixel image registration method based on SURF and Harris algorithm is proposed in registering ZY-3 image. The images obtained by ZY-3 Satellite are different in resolution and have local deformation to some extent. The SURF points are invariant on scale and rotating and the Harris algorithm is effective and has high accuracy in the images with same scales. So in the algorithm of this article, the SURF points are firstly extracted and use to make the affine transformation to reconcile the resolution, and then , the Harris points are obtained to built the TIN and make accurate registration in each triangle area. The experimental results prove that the approach is effective for the ZY-3 image registration and the two images are well matched in details. The process of coarse registration based on SURF points can improve the effect of registration. The problem of local deformation is improved and the precision is raised to some extent.