Abstract: In displacement back analysis process，people try selecting complex models to approach the real mechanical model of roadway，but the complex models needs more inversion parameters，and needs to establish more stringent inversion theory and methods.However，there exist more difficulties in practical application.The parameter sensitivity analysis to determine parameters to be inverted was common practice in the inversion process.The sensitivity analysis on elastic-plastic mechanical parameters and side pressure coefficient of rock mass in each coal layer was conducted by using orthogonal numerical simulation test，showing the impact degree of each parameter on the displacement of different parts of roadway.Furthermore，the evaluation on the corresponding impact degree is adopted to determine the parameters to be inverted.

Key words: Inversion, Orthogonal experiment, Numerical simulation, Sensitivity analysis, Displacement