The invention discloses a novel application of sodium sulfite (Na2SO3), that is, an application in preparing medicines, health products, functional drinks or functional food for preventing hypoxia-induced injury and/or diseases related to ischemia-hypoxia. According to the invention, by using Na2SO3 as an active component in preparing medicines, health products, functional drinks or functional food for preventing hypoxia-induced injury and/or diseases related to ischemia-hypoxia, the body can be in a hypoxia (such as high altitude hypoxia, mine hypoxia, and the like ) preconditioning state, thus the purpose of preventing hypoxia-induced injury and/or diseases related to ischemia-hypoxia (such as high altitude pulmonary edema, high altitude cerebral edema, cerebral ischemia, cardiac ischemia, respiratory distress, and the like) can be achieved. The medicines disclosed herein have the following advantages: 1) obvious curative effect; 2) no toxic and side effect, and high safety; 3) low price of Na2SO3; and 4) convenience in drug use (convenience in carrying and taking).