Abstract: In order to study the influence of surrounding rock stability on supporting structure, the failure process of surrounding rock is analyzed by Markov chain. And the failure model of supporting structure of single roadway and several roadways is established respectively.On the basis of the reliability evaluation index, the dim ensionless coefficient is introduced as the reference for selecting the roadway support mode.Basis on the measured dates, the paper use the model to analysis the tunn el.The result shows that the roadway system can be regarded as a series system composed of several single roadway.Furthermore, the quantitative indicators in active support is more than that of passive support when the coefficient greater than 1.It will be contrary when the coefficient is less than 1.The quantitative indicators will be e qual when coefficient equal to 1.The reliability index of roadway system is less than that of single roadway, and the value of dimensionless coefficient determines the inf luence of supporting form on the stability of surrounding rock.