Abstract: This article studies the influence of welding process parameters(welding current,wire feeding speed,welding speed)on the forming characteristics of S32101 duplex stainless steel CMT welding.The results show that the melt width increases with the increase of wire feeding speed,but decreases with the increase of welding speed and shielding gas flow rate;The penetration depth decreases first and then increases with the increase of wire feeding speed,and decreases with the increase of welding speed and shielding gas flow rate;The excess height increases continuously with the increase of wire feeding speed,decreases with the increase of welding speed,and increases first and then decreases with the increase of protective gas flow rate.These research results are of great significance for optimizing the CMT welding technology of duplex stainless steel and promoting the development of marine engineering,nuclear power facilities,and other fields.