This study aimed to investigate the effects of different levels of dietary choline on the growth， health， and metabolism of Pacific white shrimp （Litopenaeus vannamei） under low-salinity （salinity 3） conditions compared to seawater. An 8-week feeding trial was conducted with diets containing three different levels of choline chloride： 2 500， 5 000， and 10 000 mg/kg. The results showed that under low-salinity conditions， increasing the dietary choline chloride level from 2 500 mg/kg to 10 000 mg/kg did not significantly promote the growth performance of P. vannamei （P>0.05）. However， the 2 500 and 5 000 mg/kg choline group exhibited significantly higher crude lipid content in the shrimp （P<0.05）. Additionally， the 5 000 mg/kg choline diet significantly reduced glucose levels in both serum and hepatopancreas （P<0.05）， while the 10 000 mg/kg choline group showed a significant increase in hepatopancreatic superoxide dismutase activity， enhancing antioxidant capacity （P<0.05）. Moreover， a high level of choline （10 000 mg/kg） significantly decreased the triglyceride content in the hepatopancreas （P<0.05）. The study concludes that a dietary choline chloride supplementation of 2 500 mg/kg is sufficient to meet the growth requirements of P. vannamei at a salinity of 3. However， higher dosages （≥5 000 mg/kg） play a more significant role in regulating lipid metabolism and enhancing antioxidant capacity. These findings provide a scientific basis for optimizing nutritional strategies for P. vannamei in low-salinity aquaculture.