The invention discloses an identification method for identifying <14>C nuclide in a urea [<14>C] capsule. The identification method comprises the following steps: S1, preparing a test solution; S2, respectively acquiring a beta energy spectrogram of the test solution, a beta energy spectrogram of a <14>C standard source, QPE of the test solution and QPE of a <14>C standard source; and S3, generating an identification result according to the beta energy spectrum of the test solution, the beta energy spectrum of the <14>C standard source, the QPE of the test solution and the QPE of the <14>C standard source. According to the invention, the maximum energy of the test sample can be converted through the QPE of the test sample and the <14>C standard source, which is measured under the same condition; the method has the advantages that energy calibration does not need to be carried out on the liquid flash measuring instrument, conversion is more objective and accurate through the measuring result, and the influence of subjective factors for manually judging the energy end point is avoided.