The invention discloses a nondestructive evaluation method for irradiation damage of reactor pressure vessel steel of a nuclear power station, and the evaluation method comprises the following steps: (1) monitoring the magnetic remnant MR of the same monitored position of the reactor pressure vessel steel in real time, calculating the initial magnetic remnant rate of change delta MR according to the real-time magnetic remnant MR relative to the magnetic remnant (MR) in a non-irradiated initial state, and calculating the real-time RTNDT, real-time USE, real-time Rm and real-time Rp0.2 in the irradiation damage process of the reactor pressure vessel steel; and (2) analyzing and evaluating the irradiation damage degree of the reactor pressure vessel steel based on the real-time RTNDT, real-time USE, real-time Rm and real-time Rp0.2. Compared with the prior art, the nondestructive evaluation method is economic, environment-friendly, safe and highly efficient, can realize real-time monitoring, has accuracy of data and good safety of testing operation, and can monitor the irradiation damage degrees of a plurality of positions of the reactor pressure vessel.