The volume of terrain deformation caused by debris flow can be calculated by the multi-temporal DEM derived from aerial-photography only when they are in common coordinate.This paper introduces the technique of 3D surface matching without using control points.A new algorithm,Multiply Surface Patches Matching(MSPM),is proposed to match the two temporal DEMs.The experimental results on real data sets show that MSPM is more appropriate for DEM matching in debris-flow area and has higher accuracy than that of M-LZD algorithm.