通过分析各种情况下B92量子密钥分配协议的密钥分配和安全性指标 ,得出采用非对称信源实现B92协议可以在不损失安全性能的前提下极大提高密钥分配的效率 .系统分析了非对称B92协议参量选择与性能之间的约束关系 ,给出了各种情况下的最优参量 ,同时比较了不同情况相应的密钥分配效率和安全性指标 ,获得了一种实现全局最优的非对称B92密钥分配协议 By analyzing the key assignment and security index of B92 quantum key distribution protocol under various conditions, it is concluded that using asymmetric source to implement B92 protocol can greatly improve the efficiency of key distribution without losing the security performance. This paper analyzes the constraint relationship between parameter selection and performance of asymmetric B92 protocol, gives the optimal parameters under different conditions, and compares the key distribution efficiency and security index under different conditions at the same time. Optimal Asymmetric B92 Key Distribution Protocol