Abstract: The power spectral density of UWB signal stipulated by the Federal Communications Commission (FCC) is not greater than –41.3 dBm/MHz, which limits the transmitting power of ultra wide band (UWB) signal. In order to improve the receiving sensitivity of UWB signal receiver under the condition of limited power and the ranging distance of UWB signal. A long-coherent integration algorithm is designed to improve the signal processing gain, and the simulation of the long-coherent integration algorithm is carried out on two UWB signal systems according to the IEEE 802.15.4 protocol, namely HRP UWB and LRP UWB. The simulation results show that, improving the integration length has an obvious effect on HRP UWB signal, while the gain to LRP UWB signal is limited. The simulation results provide a reference and design direction for the design of UWB signal structure, which will play an important role for the application of communication and navigation integration.