This paper discusses its geology, structure and formation of Dengjiachong section, concludes that faults are developed in Dengjiachong section, F1 is the largest fault in this area influencing the coal mine, which is regional thrust fault along the bedding located in the western flank of Yonglei syncline, distributing along its striking, dipping as the same with strata at an angle of 11-58°, average at 40°. The fault interface is gently wavy. F1 fault develops in the medium to upper Longtan formation, controlled by stratified weak structural plane, overlying the top loose sandstone of coal 6 bed. Under the strong structural stress field, F1 fault has a large displacement on its upper plate, leading to a complicated structure and missing of coal beds, or partially. Its lower plate has a simple structure with loose sandstone as a good protective layer to the lower coal seam, where coal seams are well preserved. Economic coal seams are successfully discovered by using the theory of thrust fault, overturning the points of no coal in this area, offering references for searching coal under the thrust faults in the new region.