In signal simulation, MATLAB has powerful communication simulation and simple graphic function, and is an ideal simulation tool. However, there are many simulated signals, which are not easy for users to check, and the simulation program is called by multiple routines, so the portability of the program is poor. But VC++ is the main application development environment under windows, and its development process has the characteristics of beautiful interface, fast program execution and easy maintenance and upgrade. Based on the above two characteristics, this software realizes signal simulation by calling MATLAB through VC++. This paper first introduces six methods of mixed programming with VC++and MATLAB, and expounds this method in detail, and then realizes signal simulation by combining with simulation program.