To repari the trubine runners that suffer from air corrosion and wear at a cretain hydraulic power station, a special\|purpose robot for on\|the\|spot reparation of Francis burbine vane is recommended as it has some good features like efficiency, reliability, adaptability and high precision. By using the robot the previous working mode of welding and polishing by hand is abolished and in addition the time for reparation is saved and the degree of precision is raised.