Fe₃O₄@SiO₂@CPB magnetic nanoparticles were prepared by a simple synthesis method and characterized by transmission electron microscopy (TEM). The effects of the initial concentration of congo red, the reaction temperature and the pH valueon the adsorption effect were studied．The results showed that the adsorbent has better adsorption capacity for congo red. The amount of adsorption increases with the increase of congo red concentration and temperature, while the pH had little effect on the adsorption amount. The adsorption kinetics showed that the Fe₃O₄@SiO₂@CPB adsorption process for congo red was more consistent with the pseudo second-order reaction model. The isothermal adsorption linear fitting showed that the adsorption process was more in line with Langmuir adsorption, and the maximum adsorption capacity was about 434.783 mg/g.