The Yinggehai Basin is rich in low-permeability gas reservoirs and represents a key area for offshore natural gas reserve growth and exploration in China. The prediction of "sweet spot" reservoirs is crucial for the effective exploration and development of such low-permeability reservoirs. However, the low-permeability reservoirs in this basin are influenced by multiple factors including sedimentation, diagenesis, and subsequent alteration, resulting in complex petrophysical properties, strong heterogeneity, and insufficient understanding of their spatial distribution. These challenges lead to notable difficulties in sweet-spot prediction using conventional geophysical methods, characterized by low accuracy and high ambiguity. To address these issues, this study systematically conducts targeted research. First, systematic petrophysical experiments based on core samples are performed to identify key geological factors controlling reservoir permeability. Second, petrophysical patterns are analyzed, and a seismic response template characterizing sweet-spot reservoirs is established. Furthermore, integrated techniques such as AVO forward modeling, pre-stack seismic inversion, and seismic facies-constrained permeability prediction are employed to develop a geophysical evaluation method suitable for low-permeability gas reservoirs in the Yinggehai Basin. Practical exploration results demonstrate the effectiveness of the proposed method, providing support for the efficient exploration and development of offshore overpressured low-permeability gas reservoirs.