Abstract: Aiming at the triangle surface reconstruction of multi-nesting and multi-branched complex slicing contour sets,a new approach based on contours topology classification coding and structure identification is proposed.It decomposes complex cross sectional contours into several single-layered contour segment subsets and end-polygon subsets,so called DS-P method in this paper.A new topology coding scheme is devised.The rules are proposed for determining contour matching relationship,branch and branch type.Meanwhile,it designs software architecture and operating process of surface reconstruction system of arbitrary complex slicing contour sets.The experiment results show this algorithm is efficient and reliable.It deals better with ambiguity and branch problems of contour matching and effectively solves surface reconstruction problems of edge overlapping,multiple interleaved inside the projection plane,contours nesting,severe offset of contours,and contours releasing etc.,compared with classical methods or BPLI,which fails to solve those problems.