Abstract: The grain-boundary characteristic distribution of copper-nickel BFe10-1-1 alloy determines its corrosion resistance. In order to adjust the grain-boundary characteristic distribution to improve its corrosion resistance, the grain-boundary characteristic distribution of BFe10-1-1 copper-nickel alloy with different Y content was analyzed by electron backscattered diffraction (EBSD). Based on the connectivity and triple junction of grain-boundary, a numerical calculation method of grain-boundary image features was proposed, and a corrosion resistance prediction model of copper-nickel BFe10-1-1 alloy was established. The characteristics of grain-boundary image and its effect on corrosion resistance of the alloy were studied by simulated seawater corrosion experiment. The results showed that the better the connectivity of grain-boundary was, the worse corrosion resistance of BFe10-1-1 copper-nickel alloy was. Too many triple junctions would increase the proportion of grain-boundary, which deteriorated the corrosion resistance of the alloy. Compared with the first two, the angle distribution in the triple junction had a greater impact on the corrosion resistance of the alloy. The accuracy of the corrosion resistance prediction model was 81.88 %, and the predicted values of the model agreed with the real values of corrosion resistance.