Abstract: No.14 coal seam of Ganzhuang Coal Mine is affected by the mining of upper No.8 coal seam, and the mine pressure is strong.In order to determine the working resistance of support during the mining of the lower coal seam, this paper uses theoretical analysis, numerical simulation and field measurement to study the roof structure and working face support resistance of the lower coal seam mining in the close distance coal seam.The research shows that the depth of floor damage after No.11 coal seam mining is 4.3 m, and the roof of No.14 coal seam belongs to the partial damage type of bearing layer.The theoretical calculation shows that the support resistance of the working face after the mining of No.14 coal seam is 7 043.24 kN.The numerical simulation shows that after the lower coal seam is mined to 100 m, the roof plastic zone and the upper coal seam goaf form a periodic connection, and the maximum support resistance during the mining period is 6 611.5 kN;the maximum resistance of the support is 6 769 kN,which is less than the rated working resistance of the support.The research has reference for guiding the design of support parameters and optimizing the mining scheme in close distance coal seam mining.