Abstract: Angle-gather synthesis methods based on Zoeppritz equations that describe seismic reflection at an interface, generally performing convolution-based synthesis using wavelets from a unified source, fail to effectively characterize wavefield propagation, thin-layer tuning effects, and energy transmission losses in complex layered media. To address this issue, this study proposes an angle-gather synthesis method that incorporates the influence of overlying strata. The proposed method employs layer reflection units as basic computational elements and introduces an incident wavelet matrix. In the frequency domain, the proposed method comprehensively incorporates intralayer multiples, converted waves, thin-layer interference, and transmission responses during both downgoing and upgoing seismic wave propagation, ultimately outputting angle gathers directly. The proposed method was validated through forward modeling of various models. The results demonstrate that compared to the angle-gather synthesis method based on the exact Zoeppritz equations, the proposed method can provide a more comprehensive characterization of energy attenuation and complex wavefield during seismic wave propagation. It yields more reliable amplitude responses of deep strata while also maintaining consistent amplitude variation with incident angle (AVA) of PP and PS waves. Overall, this study provides a more robust theoretical and methodological foundation for pre-stack forward modeling, AVA analysis, and reservoir prediction.