The invention provides a ventilating and cooling system installed inside an indoor transformer room. A transformer is installed inside the transformer room; heat radiator is installed on the transformer; an air supply opening is positioned at the lower part of the sidewall of the transformer room; an exhaust outlet is positioned at the upper part of the transformer room; an air conveying device and an intelligent control unit are installed inside the transformer room, wherein the air conveying device is used for conveying air into the transformer room, and the intelligent control unit is usedfor controlling the air conveying device; a control signal of the intelligent control unit is from a sensor; the air conveying device comprises a fan and an air flow adjusting device; the fan is installed at the air supply opening; the air flow adjusting device is connected with an air outlet of the fan and is used for guiding the air flow sent out from the fan to the lower part of the heat radiator; the transformer room is also internally provided with an indoor air flow guiding device for changing the flowing direction of the air flow sent by the fan into an upward direction; and the indoorair flow guiding device is installed at the lower part of the heat radiator. The ventilating and cooling system provided by the invention has the advantages that (1) a ventilating system capable of effectively making the air flow pass through a region which is easily superheated is built, and the ventilation and cooling efficiency is improved; (2) the use of a roof ventilator which may generate relatively large noises is avoided, so noises are reduced; and (3) the fed fresh air directly enters the heat radiator to have heat exchange, so the energy consumption of an air supply unit is reduced.