To solve the issues of calculating gas loss quantity during sampling,simulated gas desorption process of the consumingly destruct coal with the assembly simulation testing device.Through an analysis of the simulation test datum using SPSS software, established a new formula that can be better description on gas desorption process,more accurate calculation of the gas loss quantity during sampling process,and calculating re- leasable gas quantity during a certain period.Aimed at the new formula,the best time of taking sample is confirmed 3 minutes for consumingly destruct coal,the computative error is less than 10%.Through experiment at laboratory and locale,the new formula could well describe consumingly destruct coal gas desorption law,and it has high calculation preci- sion of gas loss quantity in sampling and desorption quanlity.