A refrigeration system and a refrigerating appliance. The refrigeration system includes: a refrigeration assembly including a compressor, and an evaporator, forming a refrigeration circuit; and a defrost bypass pipeline connected to the refrigeration circuit for circulating refrigerant from the compressor to generate heat; the defrost bypass pipeline is thermally connected with the evaporator to heat the evaporator. By adding a defrost bypass pipeline connected to the refrigeration circuit and thermally connecting it with the evaporator, the evaporator can be heated for defrosting when the refrigerant from the compressor flows through the defrost bypass pipeline. Since the refrigerant from the compressor can produce a significant amount of heat when passing through the defrost bypass pipeline, this manner of defrosting can enhance the defrosting rate of the evaporator and enable quick, efficient, and thorough defrosting.