The reasonable supporting structure plays an important role in ensuring the forming quality of the parts in the selective laser melting process. The Thin-walled support is the most widely used type of the supporting structure. By analyzing the process elements of thin-walled support structure and describing the automatic generation process of thinwalled grid support structure based on STL model, the algorithm of automatic generation of thin-walled support structure of separate area is proposed and the corresponding software functions are developed. The feasibility of the implementation method is verified by generating the thin-walled partition support structures for parts.