Abstract: To address the diverse threats faced by the on-board network security of high-speed trains and the lagging operation and maintenance of network security, this paper constructed an operation and maintenance management system of new generation EMUson-board network security based on vehicle ground collaboration. It established a closed loop of safety monitoring, risk assessment, emergency response, and continuous optimization that ran through the entire process and covered all aspects from three levels: operation and maintenance technology, standard system, and operation and maintenance support, in order to ensure the safety and stability of EMUs operation. The effectiveness and feasibility of the system have been verified through practical application.