The invention provides a method for evaluating radiation damage of a reactor pressure vessel based on magnetization work. The method for evaluating the radiation damage of the reactor pressure vesselbased on the magnetization work comprises the following steps that S1, testing is carried out to obtain initial magnetization work W<0> of reactor pressure vessel steel; S2, real-time testing is carried out to obtain magnetization work W of the reactor pressure vessel steel after irradiation damage during normal operation of a nuclear power plant; S3, mechanical property data R of the reactor pressure vessel steel are calculated according to the initial magnetization work W<0> and the magnetization work W; and S4, the irradiation damage degree of the reactor pressure vessel steel is evaluatedbased on the mechanical property data R. According to the method and the device for evaluating the radiation damage of the reactor pressure vessel, the mechanical property change data of the reactor pressure vessel steel are obtained through the calculation of a magnetization work parameter, so that the real-time, on-line, continuous and intelligent monitoring of the radiation damage degree of thereactor pressure vessel is realized, and the method and the device have good popularization and application values.