Abstract: Taking C₄ coal seam of Guancang Coal Mine in Guizhou as a sample,the adsorption experiments were carried out at 30 ℃,40 ℃ and 50 ℃,and the adsorption potential theory and adsorption heat theory were used to predict the isothermal adsorption curve of coal at 40 ℃ and 50 ℃,and the higher prediction accuracy was obtained.The research results show that the adsorption potential theory and adsorption thermal theory can get high prediction accuracy.The former is better than the latter,the error distribution of the former is better than that of the latter.With the increase of pressure,the relative error of the adsorption potential theory decreases gradually.The relative error of the adsorption thermal theory decreases and then increases with the "U" type,and the minimum is at about 4.5 MPa.