The accurate estimation of coal resource reserves has important guiding significance for the development planning and safety production of coal mines. It is very important to choose a scientific and reasonable estimation method. Based on the actual mining and development of Menkeqing Coal Mine, this paper used the geological block method to estimate the resource reserves of each coal seam in detail. Combined with the geological characteristics of the estimated area, the key parameters including coal seam thickness, estimated area, structural factors and apparent density of coal seam were selected. The target area was divided into blocks. The proven, controlled and inferred resources of each coal seam were estimated. And the changes of resource reserves were analyzed and commented in detail. The estimation results showed that the change of coal seam resource reserves was mainly affected by the adjustment of block area and the increase or decrease of average thickness of coal seam. The estimation results had high accuracy and reasonable method selection, which was helpful to improve the grade of coal mine reserves, make efficient use of coal resources, and provide scientific basis for mine mining.