Abstract: Deep-sea aquaculture, as an emerging aquaculture method, has gradually become an important development direction for large-scale aquaculture of large yellow croaker (Larimichthys crocea). However, achieving efficient, welfare-oriented, green and sustainable aquaculture in deep-sea environment with windy and high current speed is a problem that needs to be solved. Exploring the effects of flow velocity on the growth performance, blood biochemical indexes and antioxidant capacity of L. crocea can provide a scientific basis for determining the appropriate flow velocity of L. crocea in deep-sea aquaculture. Theexperiment was conducted by using body lengths per second (BL·s⁻¹) as flow velocity, and 36 individuals of L. crocea were randomly divided into three groups: the control group (0 BL·s⁻¹), flow velocity group A (0.5 BL·s⁻¹) and flow velocity group B (1 BL·s⁻¹) for a 35-day experiment. The results show that higher flow velocity (1 BL·s⁻¹) might reduce the body mass growth rate and feed utilization efficiency of L. crocea. In terms of blood biochemical indexes, the blood glucose increased first and then decreased with the increase of flow rate; the lactate concentration increased continuously; the cortisol content changed significantly with the increase of flow rate. The flow velocity had a significant effect on the digestive enzyme activity and intestinal structure (p=0.024). The digestive enzyme activity increased significantly with the increase of flow velocity (p=0.004). The flow velocity significantly increased the length of villi, but decreased the thickness of villi (p<0.001). The thickness of muscle layer increased first and then decreased, reducing the number of goblet cells. In addition, the alanine aminotransferase and glutamine aminotransferase decreased significantly with increasing flow velocity (p<0.001), and at a flow velocity of 1 BL·s⁻¹, the hepatic cells appeared to be edematous with fine-textured vacuolization. In summary, a flow velocity of 1 BL·s⁻¹ can reduce growth performance, increase lactate accumulation, reduce villus contact area, and decrease digestive capacity, causing liver cell edema, reducing antioxidant levels, and increasing oxidative stress. A flow velocity of 0.5 BL·s⁻¹can increase antioxidant levels, but significantly reduce alkaline phosphatase activity (p=0.014), which may lead to a decrease in immune function and an increase the risk of disease. Therefore, it is suggested to control the flow velocity below 0.5 BL·s⁻¹ in deep-sea aquaculture, which can balance the growth performance and culture welfare.