Abstract: To determine the rational width of the section coal pillar and the optimal roadway cross-section in the No.7 coal mining area of Dananhu Coal Mine, theoretical calculations, numerical simulations, and field measurements were employed for determination, leading to the following conclusions.Through theoretical calculations, the width of the plastic zone in the coal pillar with one-side mined-out was determined as X₀=7.2 m, and the rational width of the coal pillar was derived as B=19.52～24.72 m.Comparative analyses of different coal pillar widths and roadway cross-section configurations were conducted, confirming that a coal pillar width of 20 m is suitable for this mine, with the optimal roadway cross-section being a straight-wall arched section.Field measurements revealed that the maximum displacement of the roof and floor of the roadway reached 92 mm, and the maximum sidewall displacement reached 165 mm.The loads on bolts and cables did not exceed their yield limits, indicating good stability of the roadway surrounding rock and ensuring safe production.