Abstract: During electric arc spraying,the highly dynamic interaction between two metal wires,while starting arc, melting wires and transferring droplets,directly affects the microstructure and properties of the spraying coating.In this paper,a Hispec 5 type high speed imaging system was used to investigate the dynamic metallurgic process of electric arc spraying carbon steel wires.The results showed that the arc constricted on the cathode but diverged on the anode.The arc burning was not continuous by repeating the process of ignition,burning,extinguishing and ignition again during the whole spraying process.Consequently, asymmetric heating and melting occurred to the two wires.The detachment of the two melted wires to form droplets was therefore apparently different from each other.The mechanisms of arc formation and droplet transfer were discussed based on the high speed imaging results.