A fast acquisition method is proposed to improve the detection speed of direct sequence/frequency hopping spread spectrum (DS/FHSS) communication system. A novel digital wideband receiver by using folded sampling is presented to reduce the searched hopping frequencies in coarse acquisition. There are two selective filters connected with the RF downconverter in the new scheme, one of which is wideband and the other is narrow and similar as the traditional one. The acquisition is achieved on two stages: firstly, the folded sampling is used when the wideband filter is selected and the hopping frequencies on multiple Nyquist zones are folded together on the first one, then fine acquisition is performed while the narrow band filter is selected. The detection performance of the propose method is deduced through state flow graph and verified by simulation. The results show the new method performs better when compared with the traditional one. It can effectively promote the detection speed with few detection performance loss.