Abstract: Objective Resistance spot welding is a connection method commonly used in the production and manufacturing of stainless steel urban subway car. Due to three fields coupling of thermal, electrical, and structural involved in numerical analysis of resistance spot welding, it is impossible to conduct thermal elastoplastic analysis of multi-point resistance spot welding on subway cars. Therefore, it is necessary to find an economically applicable method to achieve numerical simulation of multi-point resistance spot welding deformation of large structures. Methods Results of single-point resistance spot welding thermal elastoplastic method are compared with experimental fusion nucleus in the article. Based on verification error of fusion nucleus size being less than 2%, resistance spot welding deformation results by thermal elastoplastic method and inherent strain method are compared, and inherent strain values extracted from thermal elastoplastic method are applied to deformation analysis of side wall modules of 405 welding points. Results The results show that under actual clamping conditions, the maximum deformation of side wall multi-point resistance spot welding module after welding is 1.371 mm, mainly occurring in the cap beam position at the connection of the upper and lower skin and the edge of the lower cover, which is consistent with the actual results. Conclusion This realizes application of inherent strain method of resistance spot welding in the deformation analysis of large structures, laying a foundation for subsequent process optimization.