Abstract: As the characteristic grain boundary phase of the “Ga-rich/B-poor” Nd-Fe-B sintered permanent magnets, the tetragonal RE₆(Fe,Ga)₁₄ intergranular phase enhances the coercivity via enhanced decoupling capability to isolate the adjacent RE₂Fe₁₄B matrix phase, hence attracting widespread research attention. However, the influence of RE₆(Fe,Ga)₁₄ phase on the corrosion resistance still remains unexplored. In this work, two Nd-Dy-Fe-Ga-B sintered magnets dominated by different intergranular phases were prepared and compared by adjusting the Ga and B contents. Compared to the magnet with w(Ga)=0.1% and w(B)=1% dominated by the conventional RE-rich intergranular phase, a substantial amount of RE₆(Fe,Ga)₁₄ intergranular phase was introduced in the annealed magnet with w(Ga)=0.5% and w(B)=0.9%, yielding higher coercivity and corrosion resistance. In-situ corrosion experiments further confirmed that the RE₆(Fe,Ga)₁₄ intergranular phase effectively mitigates the corrosion process, offering a promising pathway for simultaneously improved magnetic and anti-corrosion performance of RE-Fe-B sintered magnets.