The invention discloses an expiratory-positive-pressure ventilating mask with an external diaphragm pacing function. The expiratory-positive-pressure ventilating mask comprises an expiratory-positive-pressure mask and a diaphragm pacing device, wherein the expiratory-positive-pressure mask is provided with a plurality of check valves which are connected with the mask; when inspiration is performed by the mask, the check valves are opened; when expiration is performed by the mask, the check valves are closed till starting of next inspiration, and an upper airway positive pressure in expiration is established; the diaphragm pacing device comprises a sensing unit, a diaphragm pacer and an electrode; the sensing unit comprises an airflow sensor, a sound sensor, a chest and abdominal exercise sensor and an oxygen saturation sensor; the sensor unit is connected with the diaphragm pacer by respective interfaces of the sensors and emits corresponding electric pulses; the electrode inputs electric-pulse signals generated to the phrenic-nerve traveling part on the surface of a monitored person. The expiratory-positive-pressure ventilating mask disclosed by the invention has good effects for central sleep apnea and obstructive sleep apnea respectively, and the original methods of continuous positive pressure ventilation, surgical operation and mandibular correction do not have direct therapeutic effects for the central sleep apnea respectively.