Abstract:At present, the designed inter satellite communication network security encryption system has low encryption depth, which leads to high communication error rate and can not guarantee the security of inter satellite communication network. This paper introduces the blockchain technology to design a new inter satellite communication network security encryption system. In the LEO satellite network, the satellite communication network is divided into two layers: one is the satellite network, the other is the satellite network Cover, complete the system hardware design. Based on the block chain distributed digital identity encryption technology, the status of the communication network and the encryption state of the communication network are located through the encryption protection structure diagram of the public key with the block chain. The user's key is added on the basis of the openness of the blockchain. The user can communicate with the public inter satellite communication network through the user's unique key, so as to realize the security of the inter satellite communication network Encryption. The experimental results show that the inter satellite communication network security encryption system based on blockchain technology can effectively improve the encryption depth of the network security encryption system and reduce the bit error rate.