Steam generator water supply ring assembly assembling and welding positioning device and method

The invention provides a steam generator water supply ring assembly assembling and welding positioning device and method. The device comprises a bottom ring with the outer diameter smaller than the ring outer diameter of a C-shaped ring pipe, a V-shaped seat arranged in the circumferential direction of the bottom ring and a pressing plate detachably arranged at the top end of the V-shaped seat. The bottom ring is used for bearing and fixing the V-shaped seat, and the V-shaped seat is provided with a V-shaped opening for containing the C-shaped ring pipe and used for fixing the C-shaped ring pipe. The C-shaped ring pipe is fixed into the V-shaped opening of the V-shaped seat to be limited. After the C-shaped ring pipe is fixed through the assembling and welding positioning device, a connecting pipe and the C-shaped ring pipe are welded; and the assembling and welding positioning device is hoisted through a hoisting device, a water supply ring assembly is placed in a steam generator barrel assembly to be fixed,