This paper outlines the analysis method of plant operation states (POSs) under low power and shutdown (LPSD) operations, with a focus on the key steps. Using this analysis method, a set of LPSD POSs, the statistical analysis method and results of each POS duration, and a sensitivity analysis have been determined in this paper. According to the sensitivity, it is reasonable to calculate each POS duration based on existing outage records and in conjunction with the medium and long-term outage plans. This paper could provide a reference for the probabilistic safety assessment (PSA) on EPR.