Abstract: In order to investigate the influence of various welding process parameters on the welding quality and post-weld residual stress of T-shaped welded joints made from high-strength structural steel, a numerical simulation study was conducted using the SYSWELD solver. The thermoelastoplastic method was employed for this analysis, with a focus on optimizing the process parameters for joints with a plate thickness of 6 mm. Within the framework of standard general welding process specifications, the effects of welding speed, welding sequence, and welding direction on the stress field of T-shaped welded joints were systematically analyzed. The results indicate that the maximum residual stress after welding occurs at the ends of the welded joint and exhibits a trend of initially decreasing and subsequently increasing as the welding speed increases. The minimum residual stress is achieved when the welding speed is set to 24 mm/s. For double-sided welding of T-shaped plates, relatively lower residual stress is observed when two-thirds of the weld on one side is completed first, followed by the weld on the opposite side in the reverse direction.