The invention relates to the technical field of 
medical treatment, in particular to an auxiliary 
sputum excretion method for a non-invasive ventilator and the non-invasive ventilator, and solves the technical problem how to help non-invasive ventilation patients excrete 
sputum. According to the auxiliary 
sputum excretion method for the non-invasive ventilator, during the normal 
mechanical ventilation for the patients by the non-invasive ventilator, after it is determined the patient needs sputum 
excretion, the sputum excretion operation is started in each 
respiratory cycle of the patient, andthe sputum excretion operation is not stopped until it is determined that the patient needs to stop sputum excretion. The non-invasive ventilator comprises inspiration and expiration branches, positive and negative pressure air sources, a sensor unit and a 
control unit, the sensor unit monitors physiological data used for determining whether or not the patient needs sputum excretion and needs to stop sputum excretion, the 
control unit analyzes the physiological data monitored by the sensor unit to determine whether or not the patient needs sputum excretion and needs to stop sputum excretion, after it is determined that the patient needs sputum excretion, the positive and negative pressure air sources are controlled to perform the sputum excretion operation, and the sputum excretion operation is not stopped until it is determined that the patient needs to stop sputum excretion.