System and method for evaluating process risk of nuclear power plant process system

The invention discloses a system and method for evaluating the process risk of a nuclear power plant process system. The method comprises the following steps: S1, an analysis defining step: determining an analysis range and a target; S2, a node division step: dividing the production process into a plurality of nodes; s3, a deviation analysis step: analyzing and obtaining a deviation analysis result; s4, an initial event analysis step: carrying out initial event analysis, and obtaining an initial event analysis result; s5, an event tree analysis step: performing event tree analysis to obtain an event tree analysis result; s6, a protection layer system analysis step: carrying out basic analysis and obtaining basic analysis results, wherein the basic analysis results comprise a fault tree analysis result, an equipment data analysis result, a human factor analysis result and a common factor analysis result; and S7, modeling and calculation: calculating an accident sequence failure probability F and a risk frequen