Compared with traditional phosphorus adsorbents, lanthanum-based materials have stronger affinity towards phosphorus and higher environmental friendliness, which have become the research hotspots of new phosphorus adsorbents. However, in practical applications, lanthanum-based materials have problems such as difficult recycle and low lanthanum utilization. Therefore, in this experiment, the magnetic lanthanum-loaded acidified vermiculite adsorbent (LaFeAVE) with high lanthanum utilization rate, high efficiency in phosphorus removal and magnetic separation was prepared by using acid-activated vermiculite as the carrier, introducing Fe3O4 to give it magnetic properties and loading it with lanthanum by solvothermal method and precipitation method respectively. The two kinds of magnetic lanthanum-loaded vermiculite adsorbents (LaFeAVE and LaFeVE) were compared and analyzed by adsorption experiments and various characterization methods to explore the differences in their structures and phosphorus removal performance. In addition, the phosphorus removal mechanisms of LaFeAVE were investigated. The results showed that the acid activation could remove most of the impurities such as Al2O3 from vermiculite, which increased its specific surface area and the load amount of La on vermiculite. The phosphorus removal ca-pacity of LaFeAVE was 15.97 times higher than that of unmodified vermiculite. The adsorption of phosphorus by LaFeAVE was in accordance with the Langmuir isotherm model and the quasi-secondary kinetic equation. Its maximum adsorption capacity at 35 °C was 40.01 mg P/g, which was 1.30 times as much as that of LaFeVE, and its time to reach the adsorption equilibrium was shortened by half than that of LaFeVE. It could be used in a wider pH range than LaFeVE and the phosphorus removal rate of LaFeAVE was above 93% in the pH range of 3.00~8.00. LaFeAVE was more regenerative than LaFeVE. Its adsorption capacity of phosphorus only decreased by 20% after 5 repeated regenerations. Electrostatic interaction, ligand exchange and intra-sphere complexation reaction were the mechanisms of phosphorus absorption by LaFeAVE.