提出一种新的可靠度计算方法——随机边界无法。方法概念清楚、理论先进，需要输入的信息较少，节约机时而精度较高。还对边界无法作了随机性处理，编制了可求复杂结构可靠度的程序．检验证明，本方法适用于复杂结构的可靠性分析，是有前途的值得探讨的方法。 A new reliability calculation method was proposed - random boundaries could not be achieved. The method has a clear concept and advanced theory, requires less input information, and saves time and accuracy. Also, the boundary cannot be processed randomly, and a program that can obtain the reliability of complex structures has been developed. Tests have proved that this method is applicable to the reliability analysis of complex structures and is a promising method worth exploring.