The invention provides a preparation method and an application method of a magnetic adsorbent for removing nuclide uranium. The powdery uranium adsorption material is prepared from WT with the advantages of rich sources, low cost and environmental friendliness and graphene oxide (GO) with an excellent adsorption performance, and the product has strong magnetism, and can be extremely easily separated from a liquid phase under the action of a magnetic field. The magnetic adsorbent is applied to purification treatment of uranium-containing low-level wastewater in batch static adsorption experiments, the uranium removal rate is used as an observation index to study the influences of the pH value and the addition amount of the adsorbent on the adsorption effect, and the treatment effect of theadsorbent on actual production wastewater of the nuclear industry is verified. The application method of the adsorbent rGO/Fe3O4/WT prepared in the invention in the uranium-containing wastewater is studied for the first time at home and abroad, so the reasonable and full utilization of waste resources is achieved, and a new technical product and an experiment basis are provided for the purification treatment of a uranium-containing waste liquid in the nuclear industry.