Abstract: In view of the large deformation and difficult to control of the gob roadway with large mining section, taking the 3402 working face of Hongqinghe coal mine as the research background, the calculation formula of the lateral basic roof breaking position of the gob is deduced by theoretical calculation. It is concluded that the lateral basic roof of 3402 working face is broken at 3 ~ 3.5m in the coal wall. FLAC3D simulation software is used to analyze the different coal pillar width and mining height of different working faces along the gob roadway, The results show that the peak bearing stress of coal pillar is relatively small when the coal pillar is less than or equal to 6m, the mining height of the working face increases, the stable bearing area in the coal pillar gradually shrinks and decreases, the roadway span increases, the range of low value area of partial stress of roof and floor expands, and the stability of roof decreases. According to the stress distribution characteristics of high section goaf roadway in deep large mining, The width of coal pillar is determined to be 6m. Through the implementation of support optimization scheme, good field effect is achieved.