Fixed-point simulation is extremely important in the design of fixed-point FPGAs. Float-point simulation is used to verify the arithmetic, while the fixed-point simulation is adopted to evaluate the performance and verify the implementation. The design of high-precision system based on FPGAs must focus on the fixed-point simulation to reduce the error acceptable even to zero. Basing on the analysis of fixed-point simulation approaches, especially the approach with MATLAB Fixed-Point Toolbox, we propose a novel fixed-point simulation library consisting of four modules. The library works under VC environment and its basic definition module imitates operating principle of MATLAB Fixed-Point Toolbox. The aim of library is to assit setting up fixed-point simulation conveniently, easily and quickly. Finally, simulation shows effect of the library.