Nuclear power unit primary frequency modulation system switching control method and system

The invention discloses a nuclear power unit primary frequency modulation system switching control method and system, and the method comprises the steps: S1, obtaining the equipment state information of a unit when a primary frequency modulation system of the unit is in an operation state; the equipment state information comprises at least one of main equipment state information, reactor core state information, control rod state information and steam turbine state information; s2, judging whether the unit has the capability of commissioning a primary frequency modulation system or not according to the equipment state information, if so, returning to S1, and otherwise, generating a primary frequency modulation exit signal; according to the invention, when the primary frequency modulation system does not have the capability of commissioning the primary frequency modulation system, the system can be automatically quitted in time, so that the risk of human errors is reduced, the probability of occurrence of unexp