This paper introduces the principle of chirped femtosecond pulse interference ranging and typical time-frequency analysis methods, and the influences of these methods on the analysis of the chirped spectra interference signal are compared. The factors which can affect the results are studied, and these methods are used for processing the ranging data of chirped spectrum interference. The experiment comparison shows that the relative precisions of the time-frequency transform methods are all better than 6×10-7 in a range up to 65 m, with respect to the reference He-Ne interferometer data, which meets the high-precision processing requirements. Wherein smoothed pseudo Wigner-Ville distribution, continuous wavelet transform and smoothed Choi-Williams distribution perform better in processing chirped spectral data and get the expected results.