Abstract: 20Cr2Ni4 steel is a high Cr, Ni carburizing alloy steel with good hardenability, hardness and core toughness. Two processes of “carburizing+high temperature tempering+secondary heating quenching+low temperature tempering” and “carburizing+direct quenching+cold treatment+low temperature tempering”were used to heat treat 20Cr2Ni4 steel, and the microstructure, hardness, wear resistance and impact toughness were compared. The results show that the carburizing effect and surface hardness of the samples treated by the secondary heating and quenching process are better, while the samples treated by the direct quenching process reduce the quenching deformation and surface oxidation and decarburization, save energy and reduce emissions, and improve the production efficiency.