Abstract: Though CT technique has been developed for more than forty years,there are many difficulties in ensuring precision of surface reconstruction. For the Scattered Points from industrial CT image,a data pre-processing is implemented. After the process of extracting datapoint,the algorithms of fitting,interpolation and approximation is presented. Taking example for the scatter points which translate from CT image of a part by VG,the data pre-processing and approaching algorithm are implemented with VC++ and OpenGL software. The approach is proved to be correct by the example.