Abstract: Aim To propose a new approach to the detection and estimation for multicomponent chirp signals with unknown parameter using the fractional Fourier transform(FRFT). Methods The new method was investigated and simulated, based on the property of Chirp basis decomposition of FRFT and its relationship with the Wigner Ville distribution(WVD). Results and Conclusion Compared with the WVD HT method, the new FRFT based approach need not consider the cross term interference in the case of multicomponent signals, therefore the WVD interpolation from the cartesian coordinates to the polar coordinates and the two dimensional sweeping procedure of the Hough transform can be omitted.