This paper discusses a new algorithm of sub-pixels image matching and analyzes the characteristics of resampling and surface fitting methods. In order to meet the matching demands and to alleviate the computation workload, the following improvement algorithms are used. First, resample the model n-times, putt out (2n-1) sub-models, and calculate the NCs between each sub-model and image. Then choose the maximum between the sub-model and the displacement corresponding to this sub-model which requires the sub-pixel displacement. Finally, put forward a new algorithm that combines the resampling with surface fitting methods. Experimental results show the validity of the algorithm.