Research conclusions:(1)In probability action effects analysis of the supporting structure of the tunnel using Monte-carlo statistical characteristics of stochastic finite element method，it can select a random sample of 10，000 times to simulate variable;(2)The coefficient of variation of composite lining effect and coefficient of variation of load are roughly equal;(3)Action effects can be obtained by histogram accepted normal distribution and hypothesis testing;(4)By analyzing the basic random variable degree of influence on the action effects，the equivalent collapse is the most important factor affecting the height of primary support and secondary lining axial force，followed by the thickness of the structure and the elastic modulus of the material，and the biggest impact of eccentricity is the elastic reaction coefficient, in future work should strengthen the study of rock pressure and elastic reaction cofficient;(5)The calculation results can provide theoretical basis for the railway tunnel design code revision.