The invention discloses a circulation air channel of a three-door refrigerator, which comprises the following parts: a casing, an evaporator, a split chilling chamber and refrigerating chamber on the top of the casing, a temperature-change chamber on the bottom of the casing, wherein the temperature-change chamber is an integral big drawer type structure, and the chilling chamber is only equippedwith a evaporator, the chilling work, the refrigerating work, the temperature-change work use the evaporator commonly, the chilling chamber, the refrigerating chamber and the temperature-change chamber are equipped with the circulation air channel adjusted the temperature with the same evaporator. The invention saves a temperature-change evaporator by adjusting the needed temperature of the intake air quantity in every chamber space with the circulation air channel, which preferably achieves temperature-change function lonely because the temperature chamber is a lone chamber, achieves the bigchilling and refrigerating conversion, meets the users' needs, provides the simple process, the convenient repairing.