The new CBTC signaling system based on train-to-train communication (train-to-train signaling system) introduces the concept of train centered. Through the establishment of communication and cooperation between trains, the autonomous operation and control of the train is realized. The system has the characteristics of simple structure and small dependence on the wayside equipment. A train-to-train signaling system solution was proposed, and its system structure, core principles, main functions and system characteristics were studied and analyzed. The train-to-train signaling system attempts to optimize the traditional CBTC signaling system, which is worth exploring and developing.