Abstract: In order to study the influence of the width of coal pillar on the mining pressure law in the process of large mining height working face under the conditions of shallow and thin bedrock coal seam mining, a numerical simulation mining model was established for the 5103 large-height mining working face of Sujiazhai Coal Mine under different coal pillar size conditions.The results show that when the coal pillar is 3 m, the return air roadway is located in the pressure reducing zone, with a small stress concentration coefficient; When the coal pillar is 5～12 m, the entire coal pillar is completely plastic damaged, the strength of coal pillars has sharply decreased, and there is a high demand for roadway support; When the coal pillar is greater than 15 m, the range of plastic damage in the coal pillar decreases, and the strength of the coal pillar does not significantly decrease, and the support requirements are not high; According to the support effect of the coal mine, the reasonable width of the coal pillar retaining between the working face and the return air roadway is 12～15 m.The research results have certain reference for optimizing the width of coal pillars in shallow buried thin bedrock coal seam mining.