This invention discloses a method for safely transmitting sigal data of wireless locomotives including a wireless transmission channel structure and a safety transmission protocol, in which, the transmitting channels can be two modes of digital transmission broadcast stations and GSM-R: 1, since the data channel structure of the digital transmission broadcast stations is composed of a dynamic networking, a star structure, a mode of frequency alternation between stations and address selection, a transmission way and a communication protocol, it solves the problem of interference of same frequencies, conflict of transmission frames, locking the broadcast stations, signal covering, hand off and communication protocols, 2, based on the structure of the data transmission channel of the GSM-R digital mobile communication channel, the access way of loading and the ground devices and device interfaces, 3, related transmission protocol, 3-D control and signal response confirmation can secure the reliable and safe transmission.