In order to investigate the operating performance of the ocean fishing vessel refrigeration system, this paper establishes a mathematical model and experimental verification for the marine R404A stand-alone two-stage compression refrigeration system and the R404A/R23 cascade refrigeration system, and compares the impact of system evaporation temperature and intermediate temperature on the two-stage cyclic and cascade cyclic high-temperature compression ratios, high and low pressure refrigerant flow, refrigeration coefficient and thermodynamical perfectness, etc. The results show that as the intermediate temperature rises from -22°C to -7°C, compared with the two-stage cyclic, the cascade cyclic high-temperature compression ratio decreases faster, the high and low pressure refrigerant flow changes more smoothly, and under different working conditions, there are optimal intermediate temperatures to maximize the system refrigeration coefficient. When the condensing temperature is 40°C and the evaporation temperatures are -65°C, -60°C and -55°C, the cascade system refrigeration coefficient is higher than that of the two-stage system by 21.33%, 22.25% and 22.18% respectively. Under the operating conditions of -55℃~-65℃, the performance of the cascade system is obviously better than that of the two-stage system.