Abstract: This paper proposed the method that using natural gamma logging techniques to detect and research heat of radioactive elements of coal and rock strata at different depths.Studied heat rate of rock profoundly,and through the natural gamma radiation intensity calculated Dingji mine in Huainan mining field radioactive elements in different strata,crustal heat flow,mantle heat flow.Accordingly,this article reach conclusion that is Dingji coal mine belong to "hot crust and cold mantle".