UWB technology is a wireless carrier communication technology that uses frequency bandwidth above 1GHz. This essay mainly focuses on the theory of UWB and one of its most important applications, which is indoor positioning. It will explore some possibilities of UWB in the field of precise positioning. Based on the literature, the theory of UWB and the algorithm of positioning will be shown in a relatively simple way. The result shows that Ultra Wide Band (UWB) technology has the advantages of low system complexity, low power spectral density of transmitted signal, and insensitivity to channel fading. The positioning system based on UWB can be used for the real-time location management of personnel, equipment, and vehicles, as well as to view the real-time location and distribution area of the target., such as nursing home elderly positioning monitoring, to prevent the elderly from getting lost, location management of chemical plant operators, security of dangerous areas, location management of vehicles and equipment, etc.