The utility model discloses an early warning system is tracked to train, including distance survey unit, the control unit and alarm unit, distance survey unit and the alarm unit respectively with the the control unit electricity is connected, the control unit be used for to distance survey unit sends control command, distance survey unit is used for after receiving control command lieing in preceding train and the car distance between the train of back on the same traffic direction through wireless distance measurement model measurement, the control unit still is used for the basis the car is apart from control the alarm unit is used for alarming. The utility model discloses an early warning system is tracked to train can prevent knocking into the back based on wireless range finding technology train, the utility model discloses can adapt the rail line environment under multiple environment such as tunnel, ramp and the landform and physiognomy, need not rely on the existing equipment of train, can be independent of current train control system and not receive current train control system's restriction and influence.