In order to remove the low-concentration phosphate in mariculture tailwater, metal-organic framework (MOFs) material of MIL-100(Fe) was prepared by hydrothermal method. MIL-100(Fe) was then modified using hydroxyl iron oxide (FeOOH) to prepare the MOFs-loaded FeOOH composite material, labeled as FeOOH-MIL-100(Fe). The adsorption and removal effect of FeOOH-MIL-100(Fe) on reactive phosphate in water was investigated. The results showed that the synthesized FeOOH-MIL-100(Fe) possessed a well-crystallized octahedral structure with a size of about 1.5 μm. When the phosphate concentration in water was 0.50 mg/L, the adsorption removal rate of 98% for phosphate in water was obtained by FeOOH-MIL-100(Fe) after 60 min, indicated that the metal-organic frame composite material could achieve efficient removal of low concentration phosphate in water. The adsorption process of FeOOH-MIL-100 (Fe) to phosphate conformed to the Langmuir isotherm, which could be fitted with pseudo-second order kinetic equation, indicating that the adsorption of phosphate by FeOOH-MIL-100(Fe) was a single-molecular layer adsorption dominated by chemical adsorption. In the treatment for aquaculture tailwater of Takifugu rubripes, FeOOH-MIL-100(Fe) could efficiently remove the reactive phosphate in the tailwater to achieve up-to-standard discharge of reactive phosphate in tailwater of marine aquaculture.[Chinese Fishery Quality and Standards, 2022, 12(3):01-08]