The invention provides a method and device for monitoring RPV neutron irradiation damage based on magnetization work parameters. The monitoring method comprises the steps that S1, initial magnetization work W0 of reactor pressure vessel steel is tested and obtained; S2, magnetization work W of the reactor pressure vessel steel after irradiation damage in a normal operation period of a nuclear power plant is tested and obtained in real time; S3, the neutron irradiation fluence of the reactor pressure vessel steel is calculated according to the initial magnetization work W0 and the magnetizationwork W; and S4, based on the neutron irradiation damage fluence, the safety in operation of the reactor pressure vessel radiation damage is evaluated. According to the method and device for monitoring the RPV neutron irradiation damage, neutron irradiation damage fluence data of the reactor pressure vessel steel is calculated through the magnetization work parameters, and then the real-time, online, continuous and intelligent monitoring of the safety in operation of the reactor pressure vessel radiation damage is realized, so that good popularization and application value is achieved.