The authors applied wavelet analysis to the data processing in airborne radioactive survey, and analyzed the effect of wavelet used in spectral data processing. It is shown that the method of wavelet analysis for spectral data processing can gain more true and more ideal information than the traditional data processing method, and can accurately identify information which is beyond the main energy windows. Thus, the weak information included in airborne radioactive data can be obtained, and the geologists can get more information of the studied objects. The resolution of man-made radioactive nuclides can be improved by using low-energy spectral information in the airborne radioactive survey.