Abstract: In order to investigate the effects of adding different mass fractions of copper on copper cobalt alloy composite coatings, a fiber laser was used to prepare copper cobalt alloy composite coatings on 316L stainless steel substrate using laser cladding technology. Theoretical analysis and experimental verification were conducted on copper cobalt alloy composite coatings. The results indicate that, the grain types of copper cobalt alloy composite coatings mainly include dendritic and columnar crystals. When adding a copper based alloy with a mass fraction of 1%, the grain structure of the cladding layer is the densest and the grain size is the smallest. As the copper mass fraction increases, the grain size of the cladding layer gradually increases. When the mass fraction of copper added is 10%, obvious pores and enriched particles appear. The microhardness of the copper cobalt alloy composite coating has been significantly improved compared to the substrate. When adding copper with a mass fraction of 1%, the Vickers hardness of the cladding layer reaches its optimal level, reaching 540.4 HV, which is approximately 1.65 times higher than the average hardness of the substrate. After X-ray diffraction analysis of the copper cobalt alloy composite coating, it was found that, the phases in the composite coating mainly include CoC_x, Co_0.52Cu_0.48, Cr₂Fe₁₄C and other phases. After conducting energy spectrum analysis on the copper cobalt alloy composite coating, it was found that elements such as Co, Cu, Fe, and Cr in the composite coating exhibited significant diffusion between the substrate 316L stainless steel and the composite coating. As the mass fraction of copper based alloys increases, the sedimentation phenomenon of Fe and Ni elements becomes more pronounced. As the mass fraction of copper increases, the corrosion resistance of the alloy coating shows a trend of first increasing and then decreasing. The optimal corrosion resistance was obtained at 1% mass fraction. This study has certain significance for expanding the practical application range of copper cobalt alloy composite coatings.