At present, alloy materials are being widely used as wear-resistant coatings due to good mechanical properties. In this paper, electrodeposition was used to prepare a Co–Mo coating. The influence of parameters on the phase, morphology, composition, and property of the coating has been studied, and the electrochemical mechanism has been deeply studied. The study of process parameters found that when the concentration of Na2Mo4 is 0.05 mol/L, the concentration of C6H5Na3O7 is 0.15 mol/L, the pH of the solution is 7, and the temperature is 50 °C, the content of Mo in a Co–Mo coating is 39.56%, and the microhardness reaches the maximum value of 503 HV. The study of electrochemical behavior found that the optimization of process parameters bringsa positive shift in the reduction potential, an increase in the exchange current density, and a decrease in charge transfer impedance. The microhardness of a Co–Mo coating prepared with the leaching solution of Mo-containing waste after component control of the plating solution is 483.6 HV, which is valuable to the high-value recycling of Mo secondary resources.