The invention relates to the technical field of rail transportation signals, and discloses a freight train departing method based on a CBTC system and the CBTC system. The CBTC system comprises vehicle-mounted equipment of trains and a centralized traffic controlling system. The freight train departing method comprises the steps that a request for inquiring a train running chart is sent to the centralized traffic controlling system by the vehicle-mounted equipment; a train running plan of the corresponding train is obtained by the centralized traffic controlling system from a train planned running chart according to the request, and the train running plan is sent to the vehicle-mounted equipment by the centralized traffic controlling system; the vehicle-mounted equipmentprepares departing according to the train running plan; and under the circumstance that departing preparation of the train is finished, the centralized traffic controlling system conducts departing road accessing for the train according to the train running plan. According to the freight train departing method based on the CBTC system and the CBTC system, people involving can be eliminated or significantly reduced, and automatic departing is finished, so that departing efficiency of the freight trains is improved, and meanwhile, labor intensity of related personnel is effectively reduced, and the heavy-load high-density developing direction of freight railways is met.