Abstract: In order to quantitatively evaluate operator’s response implementation reliability in digital main control rooms (MCRs) of nuclear power plants (NPPs), main performance shaping factors (PSF) are identified by contextual environment analysis. Weight of the PSF are identified by analytic hierarchy process (AHP). Furthermore, the assessment model of response implementation reliability is established based on the proposed 6 model hypotheses. A case is given to illustrate the specific application of the established method. Finally, the effectiveness of the established method is validated by case and comparative analysis. Results show that the error probability estimation results of the method is consistent with that of CREAM and SPAR-H.