Abstract: A time domain (TD) solution based on uniform theory of diffraction physical optics (UTD-PO) is presen ted to analyze the multiple cylinder diffraction. Since the solution utilizes a simple recursion relation, the complicated slope diffraction in UTD is avoided, which provides an improved TD-UTD solution for multiple diffraction. The numerical results show that the improved TD-UTD solution can not only be applied to analyze the multiple-cylinder diffraction for UWB signals, but also significantly reduce the computational time.