We had first developed APR1400 simulator with the form of emulation to perform HFE V&V of the MMIS in the construction phase of Saewool 1&2 nuclear power plant. And then APR1400 simulator was developed gradually reflecting design change and transformed into the APR1400 training simulator, and finally contributed to the acquisition of the operating license. But if MMIS related problem or MMIS design change happens in the digitalized MMIS in the plant operation phase, we need to perform MMIS V&V including control logic and MMI function through the most similar testbed. But plant MMIS cannot be fully tested with the limited condition of the emulated simulator. We have come up with new method to perform operator training and MMIS V&V simultaneously. Accordingly, we adopted virtual Distributed Control System (DCS) to implement plant MMIS in the APR1400 training simulator. This virtual DCS has the same control logic and MMI function as plant is provided. Three types for simulator operation will be provided. First mode is hybrid mode which is implemented with the form of emulated MMI and real plant control logic implemented with virtual DCS for operators’ training as well as control logic V&V. Second mode is emulation mode which is implemented with the form of emulated MMI and control logic. Final mode is stimulation mode which is fully implemented with the form of real plant MMIS including control logic and MMI function. This approach provides opportunity that complex control logic such as NSSS Process Control System can be validated before real control logics are applied in plant MMIS and improves coping capability of operator due to operator’s training in the same environment as plant. Application of this method can reduce plant transient state and unexpected plant event through the resolution of MMIS fault in advance.