Abstract: The causes and control methods of weldability problems in the welding process of duplex stainless steel are reviewed. The results show that the chemical composition of base material/welding material, welding input line energy and cooling rate are the main factors affecting the two-phase ratio, harmful phase precipitation, hydrogen-induced cracking, residual stress and deformation of duplex stainless steel joints. A duplex stainless steel welded joint with good comprehensive performance can be obtained by reasonable material selection and control of process parameters. Another effective way to prevent hydrogen-induced cracking of duplex stainless steel is to avoid high hydrogen content in the surrounding environment during welding and use.