Hechuan Qujiang Bridge, with a main span of 400m, is a single main cable anchored suspension bridge with a complex surface pylon. The main girder is a separated flat steel box girder with variation in width. For the promotion of design efficiency and insurance of design quality, a new BIM-based collaborative platform named "R+GH+R" is proposed. By means of secondary development on Rhino and Grasshopper, information can be exchanged between different software systems within the platform. Through the built-in mold standard and component coding system, the BIM technology is adopted for the design of full bridge. During the design period, new technologies such as parametric batch modeling, real-time rendering, intelligent drawing, virtual reality, 3D printing and 4D construction model are applied, which improves the design quality and efficiency. The study in this paper also accumulates experience for the development and application of three-dimensional design of bridges with BIM technology.