The invention provides a locomotive positioning system based on a track circuit and DGPS, and the system comprises a ground device and a vehicle-mounted device, the ground device comprises a DGPS base station, a tracking and positioning server, a communication server, an interlocking state collecting server, a 3G base station and a plurality of tracking and positioning client, the vehicle-mounted device comprises a vehicle-mounted positioning main engine, 3G data transmission unit, a DGPS module, a display, a sensor group, a car team detector and a plurality of electron connectors. A locomotive positioning method based on the track circuit and DGPS is also provided. The system and the method can raise the detection accuracy and precision for locomotive position and offer powerful and exact data source for further optimizing the scheduling policy.