In a high safety digital main control room of Nuclear Power Plant ( NPP) ,the er-ror is more and more caused by monitoring transferring process. Aiming at the situation,the paper proposes a reliability Markov model to effectively decrease these abnormal evens. The model mainly analyzes the error probability of next monitoring transferring object in terms of current influencing factors and plant state, a reliability evaluation is proposed in this model,namely,Markov transition probabilit...