The invention provides a medical polyurethane foam dressing. The medical polyurethane foam dressing is prepared from the following components in percentage by mass: 55 to 70 percent of waterborne polyurethane prepolymer, 2 to 3.5 percent of a catalyst, 6 to 10 percent of a surfactant, 0.5 to 5 percent of a crosslinking agent, 2 to 10 percent of sodium alginate, 2 to 10 percent of sodium carboxymethylcellulose, 0.3 to 2.5 percent of an anti-yellowing agent and the balance of purified water. The formula raw materials of the medical polyurethane foam dressing, disclosed by the invention, does notcontain organotin, the toxicity of the catalyst is lower, the content of the organotin does not need to be detected when quality control is performed and the environmental protection performance is better; in addition, the Yi value is determined by using a spectrophotometer, and the difference value of Yi measured before and after irradiation is smaller than 1.5, which shows that almost no yellowing behavior is caused. The preparation method has the advantages of simplicity and no stimulation to skin; besides, the foam cytotoxicity is detected to be a first level by referring to GBT 16886.5 and the requirements are met.