Energy-saving ventilation system for public area of subway station

The utility model particularly relates to an energy-saving ventilation system for a public area of a subway station, aiming at solving the problems that excessive fresh air exists in the operation of the ventilation system of the existing subway station, and the energy efficiency level of the operation of the system is low. The utility model discloses an energy-saving ventilation system for a public area of a subway station. The energy-saving ventilation system comprises an exhaust shaft, an exhaust fan, an air conditioning unit, a station hall air supply duct, a station hall air return and exhaust duct, a platform air supply duct, a platform air return and exhaust smoke exhaust duct and a carbon dioxide detection device, an outlet of the station hall air return and exhaust duct and an outlet of the station air return and exhaust and smoke exhaust duct are respectively communicated with an inlet of the exhaust fan and an inlet of the air conditioning unit; an outlet of the exhaust fan is communicated with the