A new method for measuring the activity of uranium and plutonium nuclides in radioactive aerosol samples by liquid scintillation is introduced. The air sampling glass fiber filter membrane for filtration dust collection method is crushed and digested by microwave, hydroxide co-precipitation, acid concentration system conversion and valence state to make a solution. The solution is sequentially passed through a series ion exchange chromatographic column composed of TEVA resin and DGA resin to realize the separation and purification of uranium and plutonium. Eluting the TEVA resin with dilute hydrochloric acid to obtain a plutonium eluate; The DGA resin was eluted with dilute nitric acid to obtain uranium eluate. The α count rate measurement was performed on the eluate sample using a liquid scintillation spectrometer with α/β discrimination function. Using filter membrane of the same specification, quantitatively adding uranium and plutonium solutions, obtaining uranium and plutonium eluate according to the same processing flow as the sample, measuring and obtaining the α counting rate thereof, and obtaining the α activity of uranium and plutonium in the sample to be measured by comparison; Then the α activity concentration of uranium and plutonium in α radioactive aerosol is calculated according to the sampling volume of the sample. The experimental results show that the cascade separation and purification process of uranium and plutonium based on solid phase extraction technology can effectively remove the influence of radon and thorium daughters on the filter material, and improve the measurement efficiency; by liquid scintillation analysis, it is found that the MDCs are no more than 2.0 × 10–6 Bq/m3 for large flow air sampling at 10,000 m3.