Abstract: In order to study the influence of nanoscale pore (<100 nm) on gas adsorption capacity, the pore structure of raw coal and structural coal of three different coal samples was studied. Moreover, a temperature-pressure comprehensive adsorption model was established to analyze the gas adsorption capacity of coal. The results show that nanoscale pore (pore diameter less than 100 nm) is the decisive factor of gas adsorption strength of coal, and the specific surface area of nanoscale pore is the main factor affecting gas adsorption; under the same temperature and pressure, the adsorption capacity of Guhanshan Mine was 1.3 to 1.8 times that of Xuehu Mine and 1.02 to 1.2 times that of Pingdingshan Mine; there was a significant positive correlation between the pore capacity and gas adsorption capacity. It is feasible to predict gas adsorption capacity by establishing temperature-pressure model.