The invention provides a vehicle-mounted terminal control method which comprises the steps that a cloud end server receives a control instruction on a vehicle-mounted terminal from a mobile terminal, whether the vehicle-mounted terminal is on line is judged, and if yes, the cloud server sends the control instruction to the vehicle-mounted terminal; and otherwise, the cloud server sends an activation signal to the vehicle-mounted terminal, the network communication function of the vehicle-mounted terminal is activated, and after the network communication function of the vehicle-mounted terminal is activated, the cloud end server sends the control instruction to the vehicle-mounted terminal through the network communication function. According to method, under the situation that energy is saved, long-distance vehicles can be controlled quickly at the same time, wireless communication is achieved, and easiness, high efficiency and applicability are achieved. The invention further discloses a vehicle-mounted terminal control system and the cloud end server.