Abstract: This paper mainly introduces the cases of degradation and failure of reactor pressure vessel head (RPVH) in Pressurized Water Reactor (PWR) nuclear power plants, and the structure of RPVH of nuclear power units. It analyzed the current in-service inspection (ISI) requirements of RPVH, described RPVH ISI technology meeting the ISI requirements, and finally analyzed the technical difficult points of surface inspection and volume inspection and solutions. It proposed suggestions on periodical ISI for RPVH of domestic PWRs.