Abstract: The effects of steady magnetic field on the solidification microstructure and corrosion performance of Mg_95.5Y₃Zn_1.5 alloy were studied in the present work. The results show that, compared with the alloy without steady magnetic field treatment, the microstructure of the alloy treated by steady magnetic field is refined, and the volume fraction of the 18R-LPSO phase is reduced. The steady magnetic field treatment is beneficial to the corrosion resistance improvement of Mg_95.5Y₃Zn_1.5 alloy. With increasing magnetic field intensity, the corrosion rate of the alloys is gradually decreased. The improving of the corrosion resistance of the alloy with 0.9 T steady magnetic field treatment is more remarkable, which is attributed to the effects of the reduction of LPSO phase and the formation of 0002 basal texture.