Using oyster shells as raw material, high-purity nano-hydroxyapatite (HAP) was prepared by hydrothermal method, and silver phosphate was loaded to prepare HAP/Ag₃PO₄ nanocomposites with high photocatalytic performance. The crystal form, chemical structure and morphology were characterized by FT-IR, XPS, XRD and SEM. It was confirmed that silver phosphate was successfully loaded on HAP from oyster shells. On this basis, the application of HAP/Ag₃PO₄ nanocomposites in the field of water pollution treatment was studied. It was found that the degradation rate of rhodamine B solution with initial mass concentration of 20mg/L reached 94.2% with simulated sunlight for 4min and dosage of nanocomposites of 1.5g/L. It showed that the prepared HAP/Ag₃PO₄ nanocomposite was a highly efficient photocatalyst, which can rapidly and efficiently degrade organic pollutants in water.