To investigate the oxidation of zirconium hydride, the corrosion test on pre-hydrided SZA-4 alloy prepared by gaseous hydrogen charging method was performed in an autoclave. Results showed that under high tensile stress produced in α-Zr matrix at the oxide/metal (O/M) interface, hydride reorientation took place and led to the transition from δ-ZrH1.66 (fcc structure) parallel to the O/M interface to ε-ZrH2 (fct structure) perpendicular to the O/M interface. ε-ZrH2 oxidized faster than α-Zr matrix, and was oxidized to m-ZrO2(monoclinic ZrO2).