Abstract: In the reactor neutron fluence measurement, the activation detectors will suffer neutron radiation in several fuel cycles, with which neutron spectrum varies. Considering this factor, for the neutron fluence measurement was corrected for one batch of irradiation material for the domestic pressure vessel. Calculations show that the relative deviation for the weighted neutron fluence (E＞1.0 MeV) correction is 1.75%, reducing 3.73% compared to the uncorrected weighted neutron fluence (E＞1.0 MeV), and thus the effect of spectrum variation cannot be ignored.