Abstract:Structural fuzzy reliability an alysis is to calculate the reliability of structureconsidering random and fuzzy of structural variables simultaneously.The method used needs multi-dimensional integration,the qtiantity of calculating is too large when there are more random vari-bles,so that not easy to use in practice. This paper presents the firstorder second -moment method andfour-moment method for structural fuzzy reliability analysis and provides favourable factors for ap-plication of fuzzy reliability methed.