The pilot-operated safety valve for nuclear power plant pressurizers serves as the overpressure protection device for the reactor primary loop system. It is widely recognized as the most challenging equipment to domestically manufacture among nuclear-grade valves. To address this issue, this project was initiated ahead of schedule in 2016 and was included in the China National Nuclear Corporation's “Dragon Ascension 2020” scientific and technological innovation plan in 2017. Leveraging over 40 years of relentless research and deep expertise in safety valves, the Nuclear Power Institute has achieved breakthroughs in high-precision pilot valve and high-capacity main valve internal flow path design/manufacturing, as well as high-capacity safety valve qualification testing. This has enabled a technological evolution from single-function to multi-function, and from low-capacity to high-capacity valves. Concurrently, a comprehensive manufacturing capability and quality assurance system have been established, creating the conditions for domestic production and engineering application of pilot-operated safety valves.