The invention discloses a CBTC (communication-based train control) system based on train-train communication. The CBTC system comprises an intelligent train monitoring ITS system, an object controller, a train management platform TMC, a data communication system DCS and an intelligent vehicle-mounted controller IVOC arranged on every train. The CBTC system disclosed in the invention can reduce the ground device and cancel the ground ATP, interlocking and other devices; the IVOC can autonomously calculate the movement license and plan the driving path through information interaction with the IVOC, OC and ITS systems of front and back trains; the ITS system can automatically generate the train running control information based on the site condition to lighten the work load of an operation dispatcher, and promote the operation efficiency and service level, and send to the IVOC; The TMC acquires the limiting-velocity information of the line and sends to every train on the line, thus the safe protection of the train is realized.