The invention provides a method of using the air charging device of smart fresh air vending machine. The air charging device of the smart fresh air vending machine is provided with an air charging connector, an air charging bottle and an charging electromagnetic valve; when the device is in use, the lower plug cylinder of the air charging bottle is inserted into an upper plug cylinder, the air charging signal is transmitted using an air charging sensor to a controller, after the currencies are inputted into an currency recognition device, the opening of the air charging electromagnetic valve is controlled by the controller, the air charging bottle is charged with air through an air charging connector; when the air charging pressure reaches a set pressure value, the signal of an air closing sensor is transmitted to the controller, the closing of an air charging solenoid valve is controlled by the controller, the air charging of the fresh air is stopped; after the removal of the charging connector and the connection of the air charging bottle, the air charging connector is closed under the elasticity of an upper spring, and the air charging bottle is closed under the action of the elasticity of a lower spring.