Abstract: In order to explain the relationship between corrosion and fatigue of welded joints in steel truss structures using arc welding, analyze the safety of the structure, and study its corrosion fatigue performance through experiments. Arc welding was used to weld steel structure truss joints. After welding, the corrosion fatigue performance of the welded joint was tested, the microscopic morphology was observed, and the influence of swing during arc welding on corrosion fatigue performance was analyzed, and the influence of corrosion on fatigue performance was studied. The test results showed that increasing the number of fatigue cycles would reduce the fatigue performance of welded joints. The extension of corrosion time further weakens the fatigue resistance, and the immersion in corrosion solution leads to corrosion products in the joint. The products are more in low-current arc welding and less in high-current welding. The ultimate residual stress of swing arc welding is higher than that of non-swing welding, and the position of the ultimate residual stress is closer to the weld. During cyclic loading hours, the crack propagation rate is high in the air environment. With the increase of cyclic load, the rate in corrosive environment increases significantly.