A forward modeling method is proposed based on attribute scattering center for target time domain echo simulation in order to quickly obtain the electromagnetic response of the radar target in the time domain under the excitation of Ultra-Wideband(UWB) electromagnetic pulses. Starting directly from the target geometric model, ray tracing and diversity techniques are adopted to mark and classify all rays in space, the strong scattering source of the target is separated and quantitatively characterized. Based on the form of the attribute scattering center model, the model parameters are positively determined, the target attribute scattering center model is constructed, and the simulation calculation is performed under the excitation of the selected radiation source to quickly obtain the target time-domain echo signal. Taking a typical target simplified tank as an example, different types of UWB electromagnetic pulse signals are selected as the radiation source, and a simplified tank scattering center model is constructed based on the forward modeling method to quickly obtain radar echo signals under the excitation of a given electromagnetic pulse. Compared with the one-dimensional distance profile obtained by the high-frequency simulation method, the results of the proposed method have good consistency, which verifies the effectiveness of using the scattering center model to quickly perform echo simulation under the excitation of different radiation sources.