Building Information Modeling (BIM) is an important technology for achieving bridge informatization. However, some BIM software still cannot meet the actual needs of bridge design, and secondary development is needed to achieve bridge parametric modeling. Based on BIM software for secondary development, combined with the design ideas of designers, starting from the automatic generation of the basic steel truss system line, then defining the section of the member, matching and associating the system line with the section of the member, and finally generating the steel truss model, the closed-loop design parameters to the parameterized model of the steel truss have been achieved. A study was conducted on the parameterization of variable diameter and unequal length group pile foundations in the special pile foundation of a super large bridge. The parameterization design of the special pile foundation was achieved. The modeling efficiency and accuracy of bridge 3D design had been improved through secondary development, providing reference for the application and development of BIM parametric design of steel truss beams and special pile foundations in super large bridges.