Abstract: With high pressure canister and accurate thermoregulation system of IS 100 isotherm instrument and an electronic flow meter,a type of gas content simulation method is established.Meanwhile,a control program is combined to control data acquisition.Base on simulated results,the whole gas desorption process from coring to end can be understand and find out gas desorption regularities,get lost gas content at any time that is sited in test.The study would be available for comparing multiple approaches to calculate lost gas.