Abstract: The frequency-domain adaptive line enhancement based on matched filter (FDAMF) method is a nonlinear filter based on recursive algorithm, which greatly improves the detection performance of matched filter. Because the narrowband signal is usually used as the transmitting signal in this method, the limited available bandwidth of the signal affects the detection performance of adaptive line enhancer. A FDAMF method for wideband signal is proposed in this paper to detect remote targets. By simulation analysis, for lower input signal to noise ratio, this method can obtain higher signal to noise ratio gain and has better detection performance. Sea trials show that the processing gain of this method is about 6.24 dB higher than that of conventional method. Therefore, this method is suitable for underwater unmanned vehicle, which makes up for the shortage of spatial gain of small aperture array to achieve remote targets detection.