Abstract: The model of airborne pulse Doppler radar clutter power spectrum is analyzed. Based on the mechanism of clutter generation, range and Doppler folder is used to bring out a rapid method for reconstructing the clutter power spectrum, which has multi-pulse repeat frequency. A fiducial clutter power spectrum map is calculated in advance. The real spectrum can be obtained by two cascade reconstruction in range domain and Doppler domain. The effects generated by the change of the parameters of aircraft and radar are analyzed. The method can be used to calculate the real-time clutter power spectrum owing to its computation reduction.