Take borehole HSNCM48-1 as an example, which was at Line 48 of Heishigou ore section of equipped exploration mining area in Dulan County of Qinghai Province, FLAC3D numerical simulation software was applied to simulate the deformation of tunnel excavation; and according to the simulation results, the support measures and monitoring points were determined. Comparative analysis was made on the numerical simulation results of vertical displacement, horizontal displacement, the total displacement and plastic zone before chamber excavation supporting, and on the real values by multi-point displacement meter before and after monitoring points excavation supporting as well as the simulation values calculated by FLAC3D simulation software respectively. By the comparative analysis on the calculation results, the deformation of chamber surrounding rocks simulated by numerical simulation software can be obtained, which is very important for the displacement field analysis and the supporting measures determination.