The eggshells are modified with magnesium chloride solution to prepare magnesium-loaded eggshells (MgES) and applied to the removal of phosphate in water. The materials were characterized by XRF， SEM， FTIR and XRD. The performance of MgES on the removal of phosphate in water was analyzed by static adsorption tests on adsorption thermodynamics, isotherms, kinetics and initial solution pH. The results show that the Langmuir model can fit the adsorption isotherm well and the maximum adsorption capacity at 25 ℃ is 112.156 mg/g. The adsorption of phosphate by MgES is a spontaneous endothermic process. The adsorption kinetics follows the quasi-second-order kinetics model. Acidic conditions are conducive to its adsorption process. In addition, after 5 regeneration times, the removal rate of phosphate by MgES still is 61.22%. The application of MgES to remove phosphate can realize the recycling and reuse of eggshell waste while reducing the phosphate content in the waste water, which is of practical significance.