Abstract: To realize a fast and accurate parameter estimation of multiple linear frequency modulated signals, using the property of ambiguity function and Radon transform, the paper presents a fast algorithm for estimation chirp rates of multiple LFM signals by ambiguity function calculated by fractional autocorrelation, and by Radon transform. The result of simulation on the evaluation module board of TMS320C6701 shows that the algorithm has a better parameter performance and high computing efficiency under the low SNR.