The invention relates to a snow making system for a performance test device for a freezing and refrigerating cabinet. The snow making system comprises a water and vapor mixing and spraying-out unit, a water tank and an air compressor for supplying compressed air for the water and vapor mixing and spraying-out unit. A water outlet and a snow making water supply opening are formed in the bottom face of the water tank. A water inlet is formed in the side face, away from the water outlet and the snow making water supply opening, of the water tank. The water tank communicates with an air-cooled chiller unit through the water outlet and the water inlet to form a water-cooling circulating loop. The snow making water supply opening communicates with the water and vapor mixing and spraying-out unit. According to the snow making system, water in the water tank flows from top to bottom, the water with the low temperature flows into the water inlet and is mixed with the water in the water tank, the longer the mixing process is, the more uniform the temperature cooling is, and therefore a snow making water region with the most uniform and constant temperature is formed naturally in the bottom region of the water tank, meanwhile it is avoided with an eddy is formed in the water tank and consequently the heat is lost, the stable snow making water temperature is guaranteed, the snow making density is increased and the snow making efficiency is improved.