Abstract: The α specific activity of plutonium(Pu) and neptunium(Np) in the uranium trioxide product is an important parameter for the quality control. In this study, a simple and reliable method based on TEVA resin was established for the determination of α specific activity of Pu and Np using α spectrometer measurement in the high-uranium content sample. In this method, the uranium oxide powder was first completely dissolved into 2 mL of 5 mol/L HNO₃ with heating at 90 ℃, then 10 mL of 5 mol/L HNO₃ was added, followed by the addition of 0.1 mL of 30%(mass fraction) H₂O₂ to adjust the valence of Pu and Np to +4. Then the Pu and Np with the high-uranium extracted onto TEVA resin on the condition of 5 mol/L HNO₃+0.1 mL 30% H₂O₂ loading, while the most of interfering element U penetrated the resin, and the rest was removed using 10 mL of 5 mol/L HNO₃+0.1 mL 30% H₂O₂ elute. The losses of Pu and Np were between 1% and 6% in the loading and rinsing fraction. Finally, the Pu and Np were simultaneously eluted with 10 mL of 0.3 mol/L HNO₃+0.02 mol/L H₂C₂O₄ at a flow rate of 1 mL/min. The results show that more than 99% of U is removed through the resin separate ion: the decontamination factor of U is greater than 3.2×10⁴ using the method. And the overall recoveries of Np and Pu are ＞90%, illustrating that the developed method is suitable for the α specific activity measurement of Pu and Np in 0.1-0.5 g of uranium trioxide sample. For the analysis of six spiked samples with known amounts of Pu and Np activities, the measured values are consistent with the expected ones, the relative deviations are between −2% and 5%, indicating the robust and reliable of the developed method. The analysis of the blank procedure shows that the measurement results of Pu and Np are between 0.8 Bq and 1.3 Bq, the detection limit is 2.7 Bq/g for the 0.2 g of uranium trioxide, which meets the requirements of the spent fuel reprocessing process for the determination of α specific activity of Pu and Np in uranium oxide powder. The method has been applied to the determination of Pu and Np impurities in post-treated uranium oxides.