The invention discloses a train-ground synergetic distributed network management system and method for a high-speed rail wide-band communication system. The train-ground synergetic distributed network management system for the high-speed rail wide-band communication system comprises an in-vehicle network management subsystem, a ground data relay station, a ground network management center and a management client, wherein the in-vehicle network management subsystem comprises a function management agent terminal, a management analysis processing module, a local database, a management southbound interface module and a management northbound interface module. According to the train-ground synergetic distributed network management system and method disclosed by the invention, aiming at the characteristic of the quick movement of a high-speed rail train, wireless bandwidth occupied by train-ground management information flow is reduced, and the high-efficiency reasonable management of the high-speed rail wide-band communication system is realized.