Abstract: In order to make up for the weak links in data security protection of critical information infrastructures in railway industry, this paper analyzed the current situation of data security of critical information infrastructures in railway industry, studied the framework, characteristics and functions of data security protection platform, and put forward the idea of dynamic data security protection, used the integration technology of lightweight data encryption algorithm and secure transmission protocol to protect the life cycle of critical information infrastructures data. The platform had the ability of pre perception, in-process response and post traceability to the data flow process of critical information infrastructures. It has reference value for railway critical information infrastructures in data security protection.