Taking 20601 haulage roadway of Dahaize Coal Mine as the engineering background, this paper studies the roof subsidence control and the determination of reasonable empty roof distance in the process of roadway excavation. By constructing the mechanical model of heading roof, the calculation formulas of roof deflection in disturbed area, empty roof area and unstable support area are derived, and the effects of empty roof length, direct roof load, support strength and direct roof elastic modulus on roof subsidence are analyzed. A numerical model is established to reveal the stress distribution, plastic zone law and deformation law of surrounding rock under different length of empty roof and support strength. According to the theoretical analysis and numerical simulation results, the original support scheme was optimized, the length of the empty roof area was increased from 2 m to 3 m and the support strength was improved. The engineering application results show that the optimized scheme not only ensures the stability of the roadway, but also improves the excavation and support efficiency. The bolt support density is reduced by 35.7%, and the tunneling speed is increased from 481.8 m/month to 640.5 m/month. The research results can provide theoretical basis and practical reference for similar projects.