Due to the complex and changeable running environment of earth and rock dams，there are a large number of uncertain factors，and the earth and rock materials themselves also have significant variability and uncertainty.Therefore，it is of great significance to study the theory and methods of safety evaluation and analysis of earth and rock dams based on considering uncertain factors. This study mainly focuses on the problem of neglecting the uncertainty of soil and rock materials in the inversion calculation and reliability analysis of traditional earth and rock dam engineering.Random methods are introduced into the inversion calculation and reliability analysis process. Based on actual monitoring data，the MCMC method is used to randomly invert the parameters of soil and rock materials to obtain the random distribution of parameters，and apply it to subsequent reliability analysis. Based on the inverted samples，interval estimation in statistics is used to provide corresponding interval parameters for reliability analysis. The reliability index interval is determined through mixed uncertainty model reliability analysis to provide a method for reliability evaluation of earth rock dam engineering and other slope engineering.