The invention discloses a multistorey electrical room environment control method. The method is used for controlling ventilation of an electrical room. The electrical room comprises an upper electrical room storey and a lower electrical room storey. A cable duct is formed under the lower electrical room storey. A ventilating port is formed between the upper electrical room storey and the lower electrical room storey as well as between the lower electrical room storey and the cable duct. An intelligent control system controls a fan according to signals of temperature and humidity sensors to supply air to the upper electrical room storey, the lower electrical storey and the cable duct through air delivery ducts, so that the temperature and humidity balance of regional spaces of the multistorey electrical room is controlled, and therefore, dewing is eliminated. The multistorey electrical room environment control method has the beneficial effects that firstly, by achieving the temperatureand humidity balance of all the spaces, the inner and outer temperature difference of electrical equipment is reduced, and dewing is avoided; and secondly, data of all monitoring sensors are obtainedthrough the intelligent system, then automatic control of all control assemblies is achieved, the control scope is wide, the control precision is high, and environments in all the spaces of the electrical room can be regulated and controlled more intelligently and more efficiently.