Ventilator is a device that can effectively replace, control or change normal physiological respiration, increase pulmonary ventilation, improve respiratory function, reduce respiratory consumption and save heart reserve. It is usually composed of a ventilation control system, a monitoring system and a control display interface. Generally, the turbine speed is controlled to make the airway pressure reach the preset pressure, so as to achieve single level or double level continuous positive pressure ventilation support. It is usually equipped with medical gas low pressure hose components, alarm systems, breathing lines, humidifiers and other accessories or auxiliary function modules, which is a kind of equipment with automatic mechanical ventilation function.