Abstract: Using the LES model of chromatography as the theoretical foundation of optimized computer-simulated analysis processing of gas chromatography, an optimized simulation method that uses the retention time of multiple-ramp programmed temperature as the basic input data was proposed. By this way, the application of optimized simulation method with samples of complex components is expanded. Simultaneously, advanced and accurate computing method and programming were utilized for improving the simulation accuracy, speed and saving analysis time greatly. The program can be used for simulating the separated processing of GC with constant temperature and multiple-ramp programmed temperature. The errors of the retention are less than 5 percent and errors with width of the peaks are less than 7 percent.