Abstract：This article introduced the importance to measured the vapor-liquid equilibrium(VLE) data in scientific research and manufacturing production, and also introduced the EOS and UNIFAC(Margules model、Van Laar model、Wilson model、UNIQUAC model and so on) which can be used in the VLE data prediction. This article made great lengths to introduce UNIFAC model, including it’s theory、developing、advantage and disadvantage, and translate and edit the design procedure UNIFAC model to be software(UNIFAC Model Calculation Software) by VB . This software through data searching and computing to calculate the activity coefficient、chart of activity coefficient、VLE isotherm(isobar) ,for the use and improve the UNIFAC model provide great help.
