Abstract: An ultra-wideband(UWB) frequency adaptive detect and avoid design method based on direct sequence spread spectrum-carrier modulation is proposed for 4.2~4.8 GHz frequency band interference suppression in China. Furthermore, the composite Gaussian n-th derivative pulse is considered as UWB original pulse. Simulation results show that the proposed DAA method can meet with the China UWB spectral mask, provide the stable UWB normal transmit power and have high transmission efficiency.