Tuna purse seiner is the most efficient fishing method in modern tuna fishery. The output of purse seine fishery accounts for 60~70% of the total output of the whole tuna fishery. The main fishing objects are yellowfin tuna and bonito. Its nutritional value is very high, but tuna is not easy to store, and it is prone to qualitative change if it is not stored properly. The price of tuna is closely related to its freshness, and the freshness leads to a higher price. Therefore, the fishing and deep freezing of tuna are related to the quality of tuna that is transported to the market after refrigeration. Therefore, it is particularly important to design and study the refrigeration system of the tuna purse seiner, including the low temperature chamber.