Abstract: Massive discharge of dyes by industries into environment has posed a threat to aquatic organisms and human health. In order to reduce dye pollution,a MnFe 2 O4 @ diatomite composite adsorbent (MnFe 2O4 @ DE)with excellent removal effect of malachite green(MG)in wastewater and simple preparation method was prepared in this study. A variety of characterization methods were used to analyze structural properties of the composite and its adsorption effect on MG was also systematically studied. The results showed that the MnFe 2O4 nanoparticles were well distributed on the surface of diatomite. Compared to two monomer materials,the specific surface area(112. 1m2/g)and pore volume(0. 24cm3/g)of the composite increased significantly. The as-synthesized composite exhibited enhanced ad- sorption behavior to MG,and its maximum adsorption capacity could reach 25. 70mg/g,which was up to around 1. 89 and 1. 13 times as much as that of diatomite(DE)and MnFe 2O4respectively. The adsorption process was spontaneous and endothermic,which was consistent with pseudo-second-order kinetic model and Langmuir model. And MnFe 2O4 @ DE also showed good reusability. After 4 times of reuse,composite still had 87. 56% removal effect on MG. Therefore,MnFe 2O4 @ DE has good application potential in dye pollution control.