Surface modification of β-FeSi 2 by ZnO is verified to be an effective way to prevent oxidation and enhance thermoelectric (TE) properties of β-FeSi 2 . A simple approach is developed to fabricate well-covered, high-density and stable ZnO nanoparticles-coated β-FeSi 2 (ZnO@β-FeSi 2 ). First, β-FeSi 2 (n-type Fe 0.98 Co 0.02 Si 2 ) particles were prepared by mechanical alloying (MA) and pre-treated in sodium oleate solution to increase the polarity of the surface. Then, the pre-treated β-FeSi 2 particles were successfully coated by ZnO nanoparticles during sol–gel process. Compared with that of uncoated β-FeSi 2 , antioxidation and thermoelectric performance of ZnO@β-FeSi 2 materials is improved distinctly.