Abstract: By analyzing data of triangular elements in a large number of STL files,we found that the probability that two orderly adjacent triangular elements share at least one vertex is about 0.84 ～ 0.99,and the probability of sharing two vertices is about 0.67～0.75.This indicates that strong correlation exists in adjacent triangle elements,and there is a great deal of redundant data in files.By using the data correlation,this paper presents an effective approach to check redundant points from the perspective of probability and a fast surface reconstruction algorithm of the STL triangular meshes.Experimental results show that,because the redundant data is eliminated effectively,the new storage capacity of surface mesh data file is 25 percent of that of the original file.