The invention discloses a catalytic material of a core-shell structure: gamma-Fe2O3-Y3-xGdxSbO7 (x is not less than 0.5 and not more than 1), SiO2-Y3-xGdxSbO7 (x is not less than 0.5 and not more than 1), MnO-Y3-xGdxSbO7 (x is not less than 0.5 and not more than 1), and application of the catalytic material of the core-shell structure ; wherein particle diameters of the gamma-Fe2O3, the SiO2 and the MnO are 0.06-2 microns, the particle diameter of the Y3- xGdxSbO7 (x is not less than 0.5 and not more than 1) wrapped with a core is 0.08-1.2 microns; organic pollutants in waste water, such as pentachlorphenol, atrazine, diuron, dye rhodamin B and the like are degraded by a reaction system consisting of a magnetic field device and the catalytic material of the core-shell structure; the magnetic field device is an intensity-adjustable alternating magnetic field generator; a light source is a xenon lamp or a high pressure mercury lamp; a volume percent of the three magnetic composite photocatalytic materials occupies one third of a volume ratio respectively; the materials are uniformly distributed in a water solution and are aerated by oxygenizing; and the overall light reaction is performed under a closed and light-tight environment. A novel catalyst is loaded on the magnetic particle core by adopting a multi-target magnetron sputtering deposition method, a pulse laser sputteringdeposition method or a metal organic chemical vapor deposition method.