Based on the paste-like roadway backfill technology in the study of coal mining under the freeway in Tang’an Mine, the mining scheme of coal under the freeway is described. In order to grasp the change law of the stress and damage degree of coal pillars and surrounding rocks during the coal mining process of roadway backfill, analyze the stability of coal pillars and the amount of roof subsidence, using FLAC3D numerical simulation method, select the width of coal pillar elastic plastic zone, the vertical stress of the column and the vertical displacement of the roof are used as indicators. The influence of the 15m temporary coal pillar width on the stability of the coal pillar, the stress distribution of the surrounding rock and the sinking of the roof under the mining method are studied to verify the feasibility of the mining scheme.