The present disclosure discloses a humidification device, and a humidifier and a ventilator to overcome deficiencies in the prior art such as the heating efficiency of a ventilator being relatively low when the amount of water in a humidification device is adequate. The humidification device comprises a heating area and a liquid conveying device conveying a liquid to the heating area, the liquid conveying device comprising a liquid inlet pipeline, the liquid inlet pipeline extending into the heating area and extending to a bottom of the heating area, and a reserved interval being provided between an outlet of the liquid inlet pipeline and the bottom of the heating area. According to the embodiments of the present disclosure it is ensured that the heating efficiency may be increased and the heating time may be reduced in the case of continuous use.