Temper bead welding repair method was proposed to repair the damage of stud holes with threads in the flanges of the Reactor Pressure Vessel. The particular welding procedure was developed to avoid cold crack. And the filler material matched with the base metal was developed to achieve the basic engineering mechanical characteristics. Furthermore, fatigue properties and welding residual stresses were evaluated. Based on the design curve defined in the design code, a kind of evaluation method was established, and used for assessing the fatigue strength of the weld metal. The welding residual stresses induced by temper bead welding were estimated from engineering view, based on analyses of multiple perspectives. In addition of the mechanical performance, a series of tests were designed and conducted to evaluate the application performance.