Abstract: The safety classification methodology is important general design criteria of nuclear power plant（NPP）, and the safety class of systems, structures, and components（SSC） is vital basis for item design, procurement, manufacturing, construction, operation and maintenance.Based on the background that the safety classification method in ANS51.1-1983 was replaced by ANS58.14-2011, CAP passive NPP, taking CAP1400 as an example, was carried out reclassification according to ANS58.14-2011. The result shows that the existing design of CAP1400 can conform to ANS58.14-2011 requirements. Besides, the main differences between ANS58.14 and ANS51.1, and IAEA SSG30 are analyzed and discussed, which provide references and suggestions for the formulation of the NPP safety classification regulations and standards in China.