Abstract: In order to refine the structure of deposited metal and control the morphology and distribution of hard phase in surfacing deposit, DC transverse magnetic field was applied to the carbon arc surfacing of Cr-B-Ni-V iron based alloy system.The influence of magnetic intensity and surfacing speed on degree of hardness and wearing resistance was studied through analyzing the hardness, wearing and microstructures of the surfacing deposit.The results show that good match of magnetic field intensity and surfacing speed can improve the properties of surfacing deposit;the optimal values of surfacing deposit are 54.4 HRC and Δm=0.033 5 when magnetic field current is 3 A, surfacing current is 180 A and surfacing speed is 12 cm/min.