Based on the engineering geologic investigation on representative tunnel at-74 m level in Longdong zone of Daye Iron Mine and the wall rock's physical and mechanical properties as well as test results of acoustic wave velocity of the wall rock,the paper applies Q and RMR classification methods to determine the quality level of the wall rock of the tunnel and evaluate the stability of the wall rock.In additional to these,the paper applies 2D-finite elements software to simulate the excavated tunnel.Through comparing the results obtained by numerical simulation and engineering analogy,the more dependable evaluation results of wall rock stability have been obtained.