A railway passenger identity authentication system is designed and developed by using the application mode of "blockchain technology + asymmetric encryption + biometric identification + identity authentication" and relying on smart phone client. By the Ethereum development platform and truffle development framework, the intelligent contract of railway passenger identity authentication system is compiled and deployed. Aiming at the shortcomings of traditional railway identity authentication system, using distributed storage of passenger identity data to ease the pressure of centralized server, the system improves the security and robustness of passenger identity data. The system ensures the ownership of passenger's identity information by bioinformatics authentication, and uses asymmetric encryption technology to enhance the transparency of data under the premise of protecting passenger's privacy and realizing real-name system. The railway passenger identity authentication system based on blockchain application model can enable user identity to be stored locally and checked information abstract on the chain, realize fine-grained control of access to railway passenger identity information, guarantee the information security of railway passenger identity, and enhance the passenger experience.