The invention discloses a welding rod for equipment such as a primary device safety end and a steam generator heat transfer pipe in a pressurized water reactor power plant. The welding rod is formed by a core wire and a coating covering the surface of the core wire, wherein the core wire is the 690 nickel base alloy core wire; and the 690 nickel base alloy core wire is prepared from the componentsin percentage by weight: less than or equal to 0.03 percent of C, 3.0 to 4.5 percent of Mn, less than or equal to 0.20 percent of Si, 29.0 to 32.0 percent of Cr, 3.0 to 6.0 percent of Fe, 0.5 to 1.0percent of Ti, 0.3 to 0.6 percent of Al, less than or equal to 0.03 percent of Co, 1.5 to 2.2 percent of Nb, less than or equal to 0.10 percent of Cu, less than or equal to 0.005 percent of S, less than or equal to 0.020 percent of P, and the balance Ni and inevitable impurities. Compared with the prior art, a welding process of the welding rod provided by the invention is excellent in performance; and the physical and chemical properties of weld metal meets the strict design requirement of the pressurized water reactor power plant.