Abstract: In order to study the effect of liquid nitrogen freezing on the quality of aquatic products at different temperatures, this paper took channel catfish as the research object, and the squid was frozen by -60, -80, -100℃ liquid nitrogen. The thawing loss rate, the pressure loss rate and the cooking loss rate of the squid at different temperatures were studied. The effects of pH, color, toughness, protein model, microstructure, water distribution and other indicators provided a theoretical basis for the production and processing of industrialized salmon.The results showed that there was no significant difference in thawing loss rate, toughness, color, expressing moisture and cooking loss after quick freezing with liquid nitrogen at -60, -80 and -100℃. The pH value of amples showed decreasing trend freezed with liquid nitrogen at -60℃ and -80℃, but the pH value of samples slightly increased freezed with liquid nitrogen at -100℃.The results of SDS-PAGE electrophoresis showed that the type and content of protein in the exudate decreased with the freezing temperature of liquid nitrogen.The cell area, intercellular spaces, and ice crystal areas of all samples increased after quick freezing with liquid nitrogen at -60, -80 and -100℃, and the samples freezed with liquid nitrogen at -100℃significantly increased. Meanwhile, after low-field NMR, it was found that the fresh, -60 and -80℃ liquid nitrogen treatments did not show significant changes in water distribution after quick freezing with liquid nitrogen, but the free water treated with liquid nitrogen at -100℃ significantly increased. From the freezing rate and quality, the -80℃ liquid nitrogen quick freezing treatment is more conducive to maintaining the quality of the channel catfish.