An auxiliary sputum excretion method for an invasive ventilator and the invasive ventilator, solving the technical problem of how to help an invasive ventilation patient excrete sputum. In the auxiliary sputum excretion method for the invasive ventilator, during a normal mechanical ventilation of the invasive ventilator for a patient, after judging that the patient needs to excrete sputum, the operation of sputum excretion is initiated in each respiratory cycle of the patient until it is judged that the patient needs to stop excreting sputum. The noninvasive ventilator comprises an inspiratory limb (2), an expiratory limb (3), positive pressure and negative pressure gas sources, a sensor unit (4) and a control unit (5). The sensor unit (4) monitors physiological data for judging whether the patient needs to excrete sputum and whether the patient needs to stop excreting sputum. The control unit analyzes the physiological data monitored by the sensor unit to judge whether the patient needs to excrete sputum and whether the patient needs to stop excreting sputum, and after judging that the patient needs to excrete sputum, controls the positive pressure gas source and the negative pressure gas source to perform the operation of sputum excretion until it is judged that the patient needs to stop excreting sputum.L'invention concerne un procédé d'assistance à l'expectoration pour un ventilateur invasif et le ventilateur invasif, résolvant le problème technique de savoir comment aider un patient sous ventilation invasive à expectorer. Dans le procédé d'assistance à l'expectoration pour le ventilateur invasif, pendant une ventilation mécanique normale sous ventilateur invasif chez un patient, après avoir déterminé que le patient a besoin d'expectorer, l'opération d'expectoration est initiée lors de chaque cycle respiratoire du patient jusqu'à ce qu'il soit déterminé que le patient n'a plus besoin d'expectorer. Le ventilateur non invasif comprend une branche inspiratoire (2),
