Abstract: With the aim of studying the distribution law of residual stress in T-joints and improving the construction quality and safety of building steel structures, a test analysis of residual stress in welded T-joints of building steel structures is proposed. After determining the base metal and welding filler material, prepare different T-joint specimens according to the differences in weld foot size, welding speed, and web thickness. After setting measuring points on the specimen using the blind hole method, a static strain tester is used to collect stress values, and the residual stress at each measuring point on the specimen is calculated based on the principal stress and strain release coefficient. The experimental results show that an increase in the size of the solder joint directly leads to an increase in residual stress values, indicating that the size of the solder joint is a key factor affecting the magnitude of residual stress, and there is a positive correlation between the two; The welding speed mainly has a direct effect on the peak value of residual stress. In order to suppress the generation of residual stress during the welding process while meeting the requirements of welding quality, the welding speed can be accelerated as much as possible; When the thickness of the belly plate is small, the transverse residual stress of the welded part exhibits a tensile compressive mode, while when the thickness of the belly plate increases, the state of residual stress changes to a tensile compressive tensile mode.