Abstract: In the field of arms control verification techniques, the dismantlement authentication of nuclear warheads is an important research object. The production, category and number of the radionuclides of the explosives in the nuclear warheads with weapons-grade uranium cores (namely WgU warheads) were analyzed, aiming at studying whether the passive detection of the radionuclides of the explosives can be applicable for the source authentication of the explosives dismantled from the WgU warheads. Based on the research result, in the explosive of the WgU warhead, the number of the radionuclides with short lifetime (¹⁶N, ¹⁵O, ¹³N and ¹¹C) is few (fewer than 1). As a result, it’s impossible to authenticate the source of the explosive by detecting these radionuclides with short lifetime after the dismantlement of the WgU warhead. However, for the WgU warhead with the storage time longer than 30 years and the inner structure based on the model 1 (proposed by Steve Fetter), the radionuclide with long lifetime (¹⁴C) in the explosive can be detected after the dismantlement of the WgU warhead, which can provide important evidence for the source authentication of the explosive.