Abstract: Total radiant flux is one of the technical indicators to characterize the radiation properties of near-UV LEDs, which can be derived by measuring the total spectral radiant flux (TSRF). In recent years, the National Institute of Metrology has carried out research on the measurement technology of TSRF, and established a standard device for measuring the TSRF ranging from 350 to 1100 nm. To verify the reliability of the uncertainty assessment in the near-UV region, the TSRF and total radiant flux values of near-UV LEDs were measured using a TSRF standard measurement device and a self-built horizontal goniospectroradiometer, respectively. The comparison shows that the values obtained by the two technical approaches are consistent within the uncertainty range. The uncertainty assessment of the TSRF standard measurement device in the near-UV region is reasonable and the values are reliable.