The invention discloses an opening type medical mask which is composed of a frame, a hose, an air mixing chamber, air pipes, an oxygen bag, an air bag, an adjusting valve and pendants. The frame is a fastener capable of being clamped on the head of a human body. A section of the hose is embedded in the lower end of the frame. The lower end of the hose is connected with the air mixing chamber. Air holes are distributed in the air mixing chamber. The air pipes are installed in the air mixing chamber. The other end of one air pipe is connected with an air conveying pipeline of the oxygen bag in a communication manner, and the other end of the other air pipe is connected with an air conveying pipeline of the air bag in a communication manner. The oxygen bag and the air bag are connected to a gown of the back of a doctor in a hung manner. Gas can overflow through the air holes. The overflowed gas form an air mass on the air mixing chamber, and the air mass covers the breathing area of the mouth and the nose. Oxygen-enriched air is used for breathing of medical staff.