Cr2O3 coating was successfully prepared on the surface of 321 steel substrate by electroplating-high temperature oxidation technology. The influence of oxidation treatment and oxidation time were investigated. The microstructures, elemental distribution and morphology of the coatings were characterized by XRD, SEM and EDS, respectively. The hardness, corrosion resistance and hydrogen resistance of the coatings were tested. The results show that the obtained Cr2O3 coating has tightly combined grains with uniform grain size of about 1 μm and low porosity when the oxidation temperature at 700 oC. The existence of a Cr-O transition layer between Cr2O3 coating and the substrate enables interfaces to bond closely. And no holes, cracks and other defects are found in interfaces. The coating exhibits good corrosion resistance, heat resistance of impact performance (300 times), resistance to hydrogen permeability increased by 10.5 times.