Abstract: Electromagnetic (EM) simulation of radar signal is of great significance especially for the research of new mechanism radar systems. In this paper, a fast approach for EM echo simulation of simultaneously polarimetric radar (SPR) is proposed, based on which high-resolution radar imaging is conducted. Firstly, the wideband fully polarimetric EM scattering data was constructed base using FEKO software for a target under all incidences within 4π space. Then, the orthogonal complementary sequence waveforms are designed for the H and V transmission channels of SPR using majorization-minimization method to minimize the metric of complementary integral sidelobe level. Finally, the echo signals were assembled by calling the data base according to the specific angle and frequency ranges. To verify the proposed method, the F22 model is taken as the imaging target in the SPR simulation experiment, and the obtained fully polarimetric images were processed via Pauli decomposition, the influence from the imbalances of amplitude and phase between H and V channels was also analyzed.