Based on Teager-Kaiser(TK) power estimating operator, the novel coexisting narrow band interference(NBI) detecting algorithm for Ultra-wideband(UWB) communication is proposed in this paper. The novel algorithm can estimate the central frequency of NBI accurately by adding the standard frequency signal to the TK disposing branch and using the discrepancy frequency information provided by the TK computation. The mathematic model and simulation analysis for the novel algorithm are made in this paper. The simulation results show that the measuring NBI frequency function can be finished efficiently. Furthermore, the novel algorithm can leave out the analog mixer used widely in typical frequency measuring system and reduce the deposing complexity evidently, which can provide the important reference for development of adaptive anti–jamming technology and cognitive technology for UWB communications.