The work aims to prepare a uniform, smooth, compact and adhesive alloy coating on the surface of substrate with Mn atomicity fraction of over 20%, which had a good compatibility to the substrate. Cu-Mn alloy coating was prepared on SUS430 stainless steel in electrodeposition method in chlorate system with EDTANa2 as complexing agent. Morphology and composition variation of the coating were studied with SEM and EDS. Effects of parameters including current density, pH value, deposition time and n(Cu):n(Mn) ratio in the electrolyte on microstructure and composition of the Cu-Mn layer were analyzed. the Mn content in the coating increased with current density, pH value or deposition time provided with current density of 200~700 mA/cm2, pH value of 3~7, deposition time of 10~30 min and n(Cu):n(Mn) ratio of 1:20~1:10, and decreased with n(Cu):n(Mn) ratio. Optimal process parameters of Cu-Mn alloy electroplating are as follows: current density of 500 mA/cm2, pH value of 5, deposition time of 20 min and n(Cu):n(Mn) ratio of 1:10. A uniform, smooth, compact and adhesive alloy coating with Mn content above 20% (atomic fraction) can be prepared. The excellent Cu-Mn alloy coating is of potential application value in solid oxide fuel cell.