The discharge of wastewater containing phosphorus will lead to eutrophication and threaten ecological environment. In this article, a kind of NiMgAl-HTLC was synthesized by orthogonal experiment, which was used to remove phosphorus from wastewater. The properties of materials were characterized by SEM, EDS, TEM, XPS and BET. The adsorption mechanism was revealed by studying thermodynamics, kinetics and influencing factors in adsorption process. Finally, in order to evaluate the inhibition ability of NiMgAl-HTLC on water eutrophication, duckweed was cultured by wastewater after phosphorus removal. The results show that the optimum preparation conditions of NiMgAl-HTLC are as follows: the molar ratio of metal ions (Ni∶Mg∶Al) is 3∶1∶3, the dosage of urea solution is 20 mL, the reaction time is 10 h, and temperature is 150 ℃. The thickness of NiMgAl-HTLC nanosheets is about 10 nm, and the specific surface area is 84.98 m2·g-1. The maximum phosphorus adsorption capacity of NiMgAl-HTLC is 61.162 1 mg·g-1, and the adsorption process conforms to second-order kinetics and Langmuir thermodynamic model. The reproduction rate of duckweed in wastewater after phosphorus removal is slower significantly, indicating that NiMgAl-HTLC possess obvious inhibition on water eutrophication.