Abstract: Irradiation damage behavior of oxide dispersion strengthened phase (Y₂O₃) in 12Cr-ODS ferrite steel was investigated by electron (e^-)helium ion (He⁺), hydrogen ion (H⁺) dual-beam irradiation. The morphology change of oxide in irradiation region was observed in-site at different irradiation models. The experiment results show that oxide size is not changed obviously under 15 dpa irradiation, however, high density small voids form surrounding oxide, and the phase boundaries are changed irregularly. The volume of oxide is shrank or expanded in the specified condition. The size of oxide is damaged lightly but not dissolved, which would not affect the performance of the steel.