Many mechanical parts, such as mechanical arm requires iron-based materials with optimal mechanical property. In the paper, CoMo coating and CoMoP coating are prepared by electrodeposition on the iron substrate to greatly improve mechanical property. The electrodeposition of cobalt and molybdenum belongs to induced codeposition. It is also found that the deposition of cobalt and phosphorus is an interdependent process. Sodium hypophosphite in the plating solution can accelerate the cobalt electrodeposition and increase the cobalt content in the coating. The CoMo electrodeposited coating has 63.8% cobalt and 36.2% molybdenum while the CoMoP electrodeposited coating consists of 71.4% cobalt, 18.1% molybdenum and 10.5% phosphorus. Both CoMo and CoMoP coating are crystalline structure with Co3Mo and MoO2. The phosphorus distribution in the grain boundary and lattice of the CoMoP coating is beneficial to refine surface particles, increase surface hardness (521.13 HV0.1) and improve wear resistance (8.42×10 -3 mm 3 wear volume).