Abstract: Objective The stress concentration induced by the notch effect at welded joints significantly degrades the fatigue load-bearing capacity of steel structures. This study employs a tungsten inert gas (TIG) weld toe dressing repair process to substantially increase the weld toe transition radius and eliminate potential defects, thereby enhancing the overall fatigue strength and service life of welded joints. Methods Cruciform welded joints fabricated from Q355D structural steel were investigated. The fatigue strength and life of joints in the as-welded condition and those with TIG-dressed weld toes were quantitatively compared. Drawing on notch strength theory and the effective notch stress (ENS) method, the effective notch stress distribution at the weld toe was computed, the influence of varying weld toe radii on the local stress state was systematically analyzed, and the variation in fatigue performance between the two conditions was evaluated. A finite element (FE) model of the cruciform joint was developed to examine the effect of notch geometric parameters on local stress concentrations, enabling accurate characterization of fatigue life. Results The results show that as the weld toe radius increases, the effective stress concentration factor decreases gradually and eventually stabilizes. Conclusion Further fatigue life assessment based on the ENS method reveals no statistically significant difference in the notch fatigue life between the as-welded and TIG-dressed weld toe conditions.