Aimed at the problems of FHN model that the detection of UWB signals is restricted by the relationships between system parameters and aperiodic stochastic resonance (ASR), i.e. the known UWB signal and the adjusted intensity of noise, the cross-correlation function is derived, and a method of ASR FHN model with adjusting system parameters is proposed based on the new cross-correlation function. The proposed method is used to detect UWB-IR signal. The simulation results show that the unknown UWB-IR signal in high noise can be accurately detected by the proposed method applicable to detect UWB signal under condition of non-cooperation in low signal to noise ratio(SNR)