Machine room ventilation system control device and method for locomotive

The invention discloses a machine room ventilation system control device and method for a locomotive. The control device comprises a ventilator, wherein the ventilator is electrically connected with contacts of three three-phase relays, the contacts of the first three-phase relay and the second three-phase relay are connected with an external power supply after being connected in parallel, and the ends, away from the ventilator, of the three contacts of the third three-phase relay are short-connected. When the speed of an electric locomotive is lower, a screen cabinet and an auxiliary machine in a machine room do not operate in a full-power mode, heat dissipation amount required by the machine room is low, the ventilator operates in a low-pole motor mode, the rotation speed is low, the maximum power level is low, noise can be effectively reduced, and the environmental protection purpose is achieved. The ventilator operates in a low-pole motor mode, the output power of the ventilator is reduced, and the energy