Control circuit, control method and system of nuclear facility security level control equipment

The invention discloses a control circuit, a control method and a system of nuclear facility safety level control equipment, and belongs to the technical field of nuclear power control. A non-safety-level on/off signal contact of the control circuit is connected in series with the first change-over switch and a non-safety-level on/off relay coil; a central control room on/off button is connected with a second change-over switch in series, an emergency monitoring room on/off button is connected with the second change-over switch in series, and two series branches are connected with a normally open contact of a safety level panel manual on/off relay in parallel and then connected with a normally closed contact of an on/off state relay and a coil of the safety level panel manual on/off relay in series. A normally open contact of the non-safety-level on/off relay, a normally open contact of the safety-level disc table manual on/off relay and a normally open contact of the safety-level interlocking on/off relay ar