Abstract: In view of the problems existing in the two-dimensional design of domestic catenary, combined with the application of BIM Technology, this article researched on the BIM design system of catenary based on Inventor, discussed the system frame and requirement of BIM design for catenary, explored secondary development and key technologies for catenary design. It was hoped to implement the intellectualization for 3D design of catenary, provide ideas for the implement of 3D design system of OCS based on BIM.