Because of excellent creep resistances and fatigue properties both in medium and high temperature, the directionally solidified superalloy DZ125 alloy has been widely used as turbine blades and guide vanes in engineering. In this paper, the repairing process of DZ125 alloy was discussed. The results showed that there were many HAZ cracks formed by using common welding materials. Then a kind of now welding alloy was developed and after proper welding and heat treatments no cracks were found in the joints. The microstructures of the joints were also homogeneous and the tensile strengths of the joints were 90% of that of DZ125 alloy.