Abstract: Taking the engineering geological conditions of the first coal mining face in a certain coal mine as the basis,using field measurement method,the mine pressure changing of mining roof was analyzed.Combined with the actual situation of the stope,engineering geological model of the coal seam roof was set up and the roof strata behavior laws during mining process were simulated by using numerical simulation software UDEC.Through comprehensive comparison and analysis of two sides' results,the weighting step of mining roof was obtained.The conclusion provides a reference for follow-up mining and support of this mine.