To analysis the portable respirator in the emergency department and application effect of critically ill patients. A hospital emergency department of 89 cases of critically ill patients admitted in recent years, successively is divided into the control group(44 cases) as specified in the admission, the observation group(45 cases), giving the control group with simple artificial balloon assisted respiration after endotracheal intubation, giving observation group with portable respirator assisted respiration after endotracheal intubation, compared two groups of total effective rate, blood oxygen saturation, heart rate and breathing rate. Observation group total effective rate was 93.33 %( 42/45) was significantly greater than in the control group 79.55 %( 35/44), with significant difference (P 0.05). Observation group of patients with blood oxygen saturation, heart rate, breathing rate improve significantly superior to control group, with significant difference (P 0.05). The portable ventilator application of critically ill patients in emergency departments, can effectively improve the treatment effect, and improve the patient's breathing difficulties, make its rise in oxygen saturation, is worth promoting. www.jiuxin-med.com