Abstract: An air-cooled progressively two-stage refrigeration system comprising: a compressor; a condenser; and an evaporator, which is connected to the condenser and the compressor respectively, and the evaporator contains a high-temperature portion, a fan, and a middle-temperature portion, the high-temperature portion and the middle-temperature portion are respectively located on two sides of the evaporator, and the fan is set between the high-temperature portion and the middle-temperature portion, and air enters the evaporator from one side of the high-temperature portion, passes through the fan and then is sent out from one side of the middle-temperature portion, and a first evaporation coil is provided in the high-temperature portion, and a second evaporation coil is provided in the middle-temperature portion; wherein the fan accelerates the cooled air in the high-temperature portion to the middle-temperature portion to undergo another cooling process, so as to reduce the energy consumption of the system.