Method for online eliminating defects of large heat-resistant steel special-shaped welding joint of nuclear power station

The invention discloses a method for online eliminating defects of a large heat-resistant steel special-shaped welded joint of a nuclear power station, which comprises the following steps of: detecting a welding seam, and searching defect positions to obtain defect information; defect information is classified, the first type is that hardness exceeds the standard, and phased array detection is unqualified; the second type is qualified in hardness and unqualified in phased array detection; the third class is a hardness standard-exceeding lattice, and the phased array detection is qualified; performing same-material repair welding and post-welding heat treatment on the first type of defects on line; carrying out on-line heat-treatment-free welding on the second type of defects; carrying out on-line heat treatment on the third type of defects; detecting the repair welding seam to determine repair, and if defects exist, continuing the above steps; the defects are classified according to defect characteristics and