According to the high reliability requirement of modern aircraft, the characteristics and functions of inertial navigation system and anti-jamming antenna are analyzed. Based on the analysis results, three configuration schemes of inertial/ satellite integrated navigation system are established. The nine configuration schemes are briefly described and their reliability is calculated one by one. Because of the complexity of the system requirements, an optimal scheme evaluation method considering the factors of product economy, crosslinking complexity, size and weight is established simultaneously. Finally, an example of navigation system with high reliability requirement is given to find the optimal redundancy allocation scheme, and the effectiveness of the proposed redundancy allocation method is verified.