Safe and efficient vehicle-ground identity authentication scheme is the basis for the safe railway oper- ation. Combined with the requirements of secure data transmission of train control system for mobile communica- tion system and the development direction of railway wireless communication network, a LTE-R vehicle-ground identity authentication protocol based on pseudo-random number and hash function is proposed. The IMSI trans- mission is replaced by the anonymous identity PID generated by IMSI and random number, which solves the se- curity problem caused by IMSI leakage. The authentication process is completed by using the temporarily gener- ated authentication key NK instead of the permanent root key K, and the security of root key K is improved. The correctness of the protocol is proved by the certification test method. The analysis confirms that the LTE-R iden- tity authentication scheme proposed in this paper has good security and anonymity, and the computational com- munication consumption meets the efficiency requirements.