提出一个无线广播网络（ＲａｄｉｏＢｒｏａｄｃａｓｔＮｅｔｗｏｒｋ，ＲＢＮ）的概率有向图模型．利用该模型，证明了计算ＲＢＮ的２终点可靠性是个ＮＰ困难问题，进而提出几个保可靠性约化（ＲｅｌｉａｂｉｌｉｔｙＰｒｅｓｅｒｖｉｎｇＲｅｄｕｃｔｉｏｎ）和一个计算ＲＢＮ的２终点可靠性的因子算法． A probabilistic directed graph model of RadioBroadcast Network (RBN) is proposed. Using this model, it is proved that computing 2-end reliability of RBN is a NP-hard problem, and then several ReliabilityPreserving Reduction algorithms and a 2finishing factor algorithm for calculating RBN reliability are proposed.