The invention provides a blood oxygen monitoring emergency device, which comprises a mask body, a blood oxygen sensor, a processor, a controller, an oxygen delivery tube, an oxygen delivery tube valve, air vents, air vent valves, an exhaust tube and an exhaust tube valve. The blood oxygen monitoring emergency device disclosed by the invention not only can detect blood oxygen but also can facilitate daily carrying in trips and supply oxygen timely. On one side, the emergency device, as a normal facial mask, can shelter from dust, and the emergency device is environment-friendly, safe, beautiful and elegant, and on the other side, the emergency device, as blood oxygen detection equipment, is light and convenient and is easy to take along, and the emergency device can measure air quality anytime and anywhere; and in addition, oxygen can be delivered in accordance with the air quality, so that the facial mask, as a temporary green oxygen bar, can protect user's body health and life security.