In order to solve the problem of the t-tube die structure parametric design, secondary development of CATIA interface based on Component Application Architecture(CAA), which applies VC++6.0 on Window XP operation system is introduced in this paper. Based on the study of parameters described method of the size, location of die structure, on how to automatically generate wing structure three-dimensional shape by CATIA secondary development, and to obtain t-tube die surface, parameters of the die model are studied. The application of CATIA secondary development technology in the Visual Studio environment on the basis of the description of the structural parameters of the t-tube die structure, combined with the C++ languages programming, parametric design of the t-tube die structure is realized.