Pressurized water reactor critical process control method and system

The invention discloses a pressurized water reactor critical process control method and system. Relates to the technical field of reactor starting control. The method comprises the following steps: dividing introduction control of reactivity into two stages, controlling rod lifting of a control rod by stages according to the rod position of the control rod and the reactor period, and calculating introduction of reactivity according to the measured reactor period change condition and the rod position of the control rod, so as to judge whether the reactor reaches a critical state or not; the problem of automatic control in the reactor critical process is solved; aiming at the characteristics of nonlinearity, fast response and high risk of the reactor critical process, the reactor source region period is taken as control input, an automatic control rule is designed according to different stages, an automatic control scheme is provided, the reactor critical automatic control is realized, and the automation and in