Welding procedure qualification is the core and basic standard in the field of welding standard. At present,there are two welding procedure qualification standards in China,NB/T20002.3 and NB/T 20450.3,which increases the cost of design and manufacturing and the difficulty of supervision,and is not conducive to export. In this article, the differences in the scope of two standards,and the main technical differences about the inspection and acceptance requirement,welding variables and coverage are compared,analyzed and studied. Finally route unification solutions are given. The pioneering work on technical route unification of welding procedure qualification standards has great practical significance for perfecting the standard system of nuclear power in China,improving independence of the standard and facilitating the "go global" of China’s nuclear power.