An experimental study shows that a critical effective stress value exists, and coal permeability does not increase or decrease monotonously with temperature increase as previous researchers had thought. When effective stress is more than this value, coal permeability decreases as temperature rises; when effective stress is less than this value, the opposite law will appear. Also, based on dimension analysis and multiple regression, combining experimental data analysis, this study develops a coal permeability model, which has high accuracy. Using this study's method, a similar permeability model suitable for other target zones can be established. So this study provides a theoretical basis for coal permeability prediction.