The invention relates to a train control vehicle-mounted system. The train control vehicle-mounted system is characterized in that each independently-grouped train or wagon is provided with a set of train control vehicle-mounted system host, a set of peripheral device is arranged at each of two ends of the independently-grouped train or wagon, and a dual-redundancy train control vehicle-mounted communication network is connected with the train control vehicle-mounted system host and all peripheral devices. A method for realizing distributed redundancy configuration of the train control vehicle-mounted system comprises the following steps: arranging the dual-redundancy train control vehicle-mounted communication network penetrating through a whole passenger train or freight locomotive, arranging a set of train control vehicle-mounted system host on each independently-grouped passenger train or freight locomotive, and arranging a set of peripheral device on each of the two ends of each independently-grouped passenger train or freight locomotive. According to the invention, on the premise that high safety and high reliability of the train control vehicle-mounted system are not influenced, the quantity of the devices is minimized, the redundancy utilization ratio of the peripheral devices is improved, and the train control vehicle-mounted system has space diversity redundancy characteristics and certain space diversity disaster recovery characteristics.