Abstract: RMR is applied to analyze the rock stability，Pullman's theory is used to calculate the hardness of tunnel wall rocks，finally the phase2 finite element analysis is adopted to simulate the distribution of model stress.Combined with the results from the above three methods，the comprehensive evaluation on the stability of this tunnel of Aipu Iron Mine is obtained and some reasonable suggests to maintain the tunnel are proposed.The results show that the reasonable analysis and simulation on the stress of tunnel wall rocks can reflect the distribution of the wall rocks and provide an important role in predicting and assessing the tunnel's stability.

Key words: Stability, RMR, Pullman's theory, phase2