An adaptive method for a mode of a train car fluorescent temperature-measurement system involves two hosts, wherein the two hosts are respectively arranged at a headstock and a tailstock of a train, the adaptive method is characterized in that the hosts and interconnection boxes are in response communication, only one of the hosts is in a master control mode during normal operation, the other hostis in an auxiliary mode, the host in the master control mode needs to send an inquiry command to inquiry data of all interconnection boxes, and the host in the auxiliary mode is used for only monitoring data on a bus. By the adaptive method, complete adaptability of working modes of the two hosts of the system is achieved; when manual configuration is wrong, the system can identify and correct, the problem of manual misoperation is fundamentally solved, the fault-tolerant capability of the system is improved, and the usability and the reliability of the system are improved; and moreover, an external encoder is also omitted, the system complexity is reduced, and the cost is reduced.