Rapid load reduction method and system for high-temperature reactor

The invention discloses a rapid load reduction method and system for a high-temperature reactor. Comprising the steps that when a rapid load reduction working condition is triggered, a steam turbine electro-hydraulic control system is switched into a pressure control mode, and machine front pressure is adjusted to be stable through a pressure controller; determining a target valve position corresponding to the reactor power according to a main feed water flow measurement value of the steam generator; and when the control deviation of the pressure controller exceeds a set value, the steam turbine electro-hydraulic control system loads a rapid load reduction loop, and the opening degree of a high-pressure control valve of the steam turbine is reduced to the target valve position at the speed of-100%/min. The multi-module nuclear power unit can maintain the stable pressure at the outlet of the steam generator, prevent the tube plate of the steam generator from being impacted excessively, guarantee the overall se