By using transient EM scattering theory and electromagnetic wave superposition principle, and pulling-in radar fuze transfer function under dynamic effect based on the mode of multi-point scattering, this paper analyzes the target scattering properties of the ultra wide band radar fuze under the dynamic effect, builds up the target IRF, analyzes the relationships between the target's direction of electromagnetic radiation and the pulse width in simulation , and obtains how the synthetic pulse wave formed through undergoing one-dimensional UWB array radiation by Gaussian monocycle to select appropriate array beam parameters . The research is of some significant value to the design of UWB radar fuze.