Refrigerating and defrosting system

The embodiment of the utility model discloses a refrigerating and defrosting system which can improve the refrigeration efficiency, and relates to the field of refrigeratory and cold chain systems. The refrigerating and defrosting system comprises a moderate-temperature system used for moderate-temperature refrigeration, a low-temperature system used for low-temperature refrigeration and a defrosting loop, wherein the defrosting loop consists of refrigeration circulation loops of both the moderate-temperature system and the low-temperature system. During defrosting, high-temperature and high-pressure gaseous condensing agent generated by the moderate-temperature system is led to the refrigeration circulation loop of the low-temperature system and flows back to the moderate-temperature system after being defrosted and cooled by the low-temperature system, so as to bring convenience for the moderate-temperature system to conduct refrigeration cycling. The refrigerating and defrosting system is applied to refrigeratory and cold chain systems.