Abstract: Forward scatter radar (FSR) plays a significant role in the detection of low, slow, and small targets, so it is of great importance to study the echo characteristics of targets passing through the forward scattering region. In this paper, under the condition of near-field transmission and near-field reception, firstly, the ability of the Fresnel-Kirchhoff diffraction theory to characterize the actual scattered field and the total field of the target is analyzed. The results indicate that this model is effective only within a very small angle range directly in front. When the target is outside the first Fresnel zone, due to the increased scattered field produced by the induced currents on the target surface, considering only the diffraction model is no longer sufficient to accurately reflect the changes in the total and scattered fields. Then, using a rectangular plate target as a case study, the influence of target size, motion parameters, and the position in the moment of crossing on the forward scatter echo is simulated and analyzed. Finally, the results are verified by the darkroom measurements. The research results can provide theoretical guidance for the practical application of FSR.