Abstract: To improve the mechanical properties and corrosion resistance of copper alloys, the effects of different Cr element contents on the microstructure, mechanical properties, and corrosion resistance of CuNi30-xCr (x is mass ratio, x=0,1,2,3) copper-nickel alloys were studied using selective laser melting technology. The research shows that during the laser melting process, a small amount of Cr element will solidify into the α-Cu phase, and the addition of a higher content of Cr elements will promote the precipitation of Cr-rich phases; the addition of Cr elements improves the mechanical properties and corrosion resistance of the alloy, with the microhardness of the alloy increasing from 126 HV0.2 to 157 HV0.2 as the Cr content increases; when the Cr content is 3wt%, the corrosion potential of the alloy shifts positively from -0.238 V (CuNi30) to -0.210 V (vs SCE), and the corrosion current density decreases from 1.38×10?? A·cm-2 to 7.72×10?? A·cm-2, a reduction of 44%; this is due to the solid solution strengthening of the chromium element and the formation of Cr-rich second phases inhibiting the matrix anodic dissolution tendency, thereby improving the corrosion resistance of the alloy.