Abstract: To avoid low efficiency of the traditional Monte Carlo sampling method in power system reliability evaluation,a stratified uniform sampling method is proposed,which combines the advantages of stratified sampling and importance sampling.The method proposed can help avoid the complexity of constructing the importance sampling function,and reduce the experiment times by stratified sampling.Without sampling on zero fault state space,the method proposed can be effectively applied in the high reliability system.The rationality of this method is deduced in theory.Tests on IEEE-RTS 79 system and the revised system with higher reliability demonstrate the high efficiency of the proposed method.