Proposed in this paper is a multiple access scheme based on fractional Fourier transform（FrFT） to improve the bit error rate（BER） performance of ultra-wideband（UWB） system.In this scheme,with the combination of TDMA（Time Division Multiple Access） and the utilization of phase change in waveform selection,a set of orthogonal pulse waveforms are designed and applied to the ultra-wideband system.Then,based on the energy-aggregating characteristics of the signal in the order-FrFT domain,filtering is conducted to reduce the multiple access interference.Simulated results indicate that the proposed scheme effectively improves the system capacity and the orthogonality among pulse waveforms,and that the filtering in FrFT domain further improves the BER perfor-mance of the system.