Abstract: In order to realize the automatic welding of the intersecting lines of large TKY nodes instead of manual welding, the welding groove processing is completed based on the theoretical calculation of the intersecting line welding groove, the segmentation of the intersecting line welding trajectory is completed based on the theoretical calculation and simulation of the intersecting line welding trajectory, and the welding procedure for automatic robot welding is obtained based on the simulation analysis of the intersecting line welding trajectory. Based on the above welding procedures and welding process parameters, the automatic welding experiment of TKY node intersecting line is completed, and the welding quality, welding efficiency, joint organization and mechanical properties of manual welding and robot welding are compared. Finally, it is proved that the collaborative welding robot class replaces manual welding. The automatic welding of TKY node intersecting line is realized. The research results of this paper can provide a theoretical reference and practical significance for the application of collaborative welding robots in the automatic welding field of large-scale TKY joint intersecting lines.