Method and system for keeping constant temperature and constant humidity of elevator

The invention discloses a method and system for keeping the constant temperature and constant humidity of an elevator. The method includes the steps that a temperature sensor detects the temperature inside an elevator cage in real time, when the temperature is lower or higher than a set temperature, an electric heating unit conducts heating or refrigeration to transfer heat to a ventilating pipe, the ventilating pipe transfers the heat to the inner wall of the elevator cage, and the inner wall of the elevator cage dissipates the heat into the elevator cage; meanwhile, a controller controls a draught fan to run, air is sucked into the elevator cage through an air suction opening, the air penetrates through the ventilating pipe and makes contact with heat exchange fins so that the air can be heated or cooled, and hot air is exhausted out of the elevator cage through an exhaust opening; multiple humidifying and dehumidifying integrated machines are further arranged in the ventilating pipe, a humidity sensor is a