The invention relates to the technical field of medical equipment, in particular to a medical oxygen mask which comprises a mask body. Two mutually symmetric elastic bands are connected onto the maskbody, an upper breather pipe is mounted at the bottom end of the mask body, a lower breather pipe is arranged on the lower portion of the upper breather pipe, a rotary control ring is connected between the lower breather pipe and the upper breather pipe, an oxygen bag is mounted at the bottom end of the lower breather pipe, an upper embedded fixed plate is mounted inside the upper breather pipe, upper air holes are formed in the upper embedded fixed plate, and an upper sliding rail groove is formed around the surface of the upper breather pipe. The rotary control ring connected between the upper breather pipe and the lower breather pipe can manually and freely control the quantity of oxygen entering the upper breather pipe and the lower breather pipe, the respiratory capacity of patients can be adjusted according to specific circumstances of the patients by the aid of the same oxygen mask, oxygen supply requirements of different patients can be met, and clinical treatment is greatly facilitated.