Abstract: The gas outburst occurs frequently at the area where the tectonically deformed coal is located, so understanding the developmental patterns of the tectonically deformed coal is beneficial to the prediction and evaluation of gas outburst. In this paper, we take No.3 coal seam of Xinjing coal mine in Yangquan as the research object, firstly, we established the mechanical model of the lithologic disequilibrium according to the geological conditions, then with the software FLAC^3D, simulated the stress distribution of the rock surrounding seam 3 on which many sandstone lens lie. The simulation results show:because of the effect of the sandstone lens, the distribution of stress and displacement in coal and rock was unbalanced, the stress was concentrated in the scope influenced by the lens and resulted in the plastic deformation of coal seam in this area. The research results reveal that the developmental patterns of the tectonically deformed coal in seam 3 was affected by the lithological disequilibrium, and then confirmed that the sandstone on the roof had a control effect on the tectonically deformed coal zone.