Abstract: Focusing on the seasonal distribution of nitrogen and phosphorus nutrients in the Pearl River Estuary, this paper uses Pearson’s correlation analysis and “nutrient-salinity” double-end member model to discuss the main influencing factors and potential sources of nitrogen and phosphorus nutrients. The water body was assessed for eutrophication. The results showed that the nutrient concentrations of nitrogen and phosphorus in the Pearl River Estuary were relatively high (mean values were 0.72 mg/L and 0.021 mg/L, respectively), showing a decreasing trend from the top of the estuary to the open sea. In other seasons; the dilution and mixing effect of open water mass on nitrogen nutrients is higher than that of phosphorus nutrients; the results of the “nutrient-salinity” double-end element model show that in summer and autumn, the decrease of inorganic nitrogen concentration is mainly due to the absorption of marine organisms (Chlorophyll a concentration>10 µg/L), while in autumn and winter, the input of inorganic nitrogen is mainly reduced due to the mixing of estuary water and small runoff; active phosphate mainly comes from sewage discharge from nearby cities, and its concentration reduction is mainly due to It is caused by phytoplankton absorption and sediment adsorption; the growth of phytoplankton in this sea area is mainly limited by phosphorus, and the overall water environment is moderately eutrophic, and there is a high probability of eutrophication disasters in summer.