Ultra Wideband (UWB) has the advantages of high positioning accuracy and good security. It has a broad application prospect in the field of navigation and positioning. In this paper, we discuss a kind of DS-UWB based navigation and positioning system. The proposed system use the chaotic sequences by aggressive Logistic and UWB pulse as the spread spectrum codes of navigation signals. And then, the navigation signal is transmitted by navigation sources. The proposed system can improve the security of satellite navigation system. What’s more, the proposed system can build an independent navigation system to provide the PNT services.