Abstract: The automatic gas tungsten arc weld (GTAW) process parameters for 4 mm thick 2205 duplex stainless steel plate were simulated by finite element software. The weld morphology features under different process parameters were analyzed, the optimized process parameters were obtained. Based on the optimized process parameters, the welding of the 2205 plate was carried out, and the microstructure and properties of the joint were analyzed and tested. The results showed that with the simulation optimized process parameters, welded joints of high-quality could be obtained, that the microstructures of different zones of the joint were of two-phase structure, and that the mechanical properties, cold bending properties and intergranular corrosion properties of the joint could meet the actual requirements.