Aimed at the problems that parameters are very difficult to be estimated and multi-component LFM signals are difficult to be separated by using the FourierBessel transform (FBT) algorithm, a new method based onk resolution FB (k -FB) series in conjunction with the Dechirp technique is proposed. The k resolution is introduced into the FB series, and the relationship between the frequency content and the order of k -FB series is derived. Meanwhile, the positive correlation between the kresolution and the estimation precision is proved. With the Dechirp technique and the kFB series expansion, multicomponent signal separation and parameter estimation are both realized. The performance of the signal separation precision under various SNR conditions with different kresolution and signal power ratios is simulated. Moreover, a performance comparison between the proposed method and the traditional fractional Fourier transform (FrFT) based method is also provided. The simulation results show that the method is valid.