Accurate prediction of binding affinity is crucial for rational drug design and discovery. This work proposes a novel scoring function that models multi-level, multi-body atomic interactions using graph-based representations. The method constructs interaction graphs with both pairwise and triplet-wise atomic features and uses feature fusion to improve accuracy while maintaining model simplicity. Across PDBbind v2013, PDBbind v2016, PDBbind v2020, CSAR-NRC-HiQ, and PDBbind-Redocked, the model consistently outperforms state-of-the-art scoring functions, achieving Pearson correlation coefficients up to 0.877, while remaining robust under strict data-leakage controls and realistic docking conditions.