Abstract: In this paper, through the combination of theoretical analysis and numerical simulation, it is concluded that the particularity of coal pillar size should be fully considered when the complex roof roadway is disturbed. In the design of roadway support, we should pay attention to the control of roof rock and increase the support surface area as much as possible. Taking Xinyuan coal mine roadway as the research object, according to the theoretical calculation, the minimum size range of coal pillar is 6.07-7.12m. On this basis, through numerical simulation of stress and deformation characteristics of coal pillars with different sizes, it is concluded that when the width of coal pillar is 8m, the safety of roadway under the influence of secondary mining advance can be ensured, and the bearing capacity of coal pillar can be fully utilized. The research results have been applied in 2203 track crossheading of Xinyuan coal mine, and good surrounding rock control effect has been achieved .