Abstract: As a new reservoir type, the fault-fracture unit is becoming a research focus and key direction for the exploration of tight sandstone gas reservoirs in the Xujiahe Formation of the Sichuan Basin. Gas in the third member of Xujiahe Formation (Xu-3 Member) in the Dayi area, western Sichuan Basin, typically occurs in tight sandstones with low porosity and low permeability. Faults are well-developed in this area, and both faults and fractures play a crucial role in connecting hydrocarbon sources and improving reservoir porosity and permeability. Therefore, this area has the fundamental conditions for the formation of fault-fracture gas reservoirs. In this paper, the fault-fracture control on Xu-3 gas accumulation is analyzed, followed by the genetic classification of fractures. Seismic prediction of fault-fracture units is then implemented based on multi-attribute fusion. The following results are obtained. First, the matrix porosity of Xu-3 gas reservoirs in the Dayi area is too low to support hydrocarbon migration and accumulation. The fault-fracture network acts as the dominant reservoir space and migration channels. Second, 3D illumination based on the symmetry attribute mitigates the impacts of noise and acquisition footprints and improves fault resolution by enhancing linear features. The predicted fault distribution is therefore geologically plausible. Third, the curvedness attribute is sensitive to fold-related fractures, and the combination of the illumination volume with curvedness provides a better characterization of fault-fracture units. Fourth, multi-attribute fusion integrated with 3D visualization enables the comprehensive display and 3D characterization of fault-fracture units. This integration is beneficial for well location deployment and optimization. This method achieves precise characterization of fault-associated and fold-related fractures as well as fault-fracture units, and provides an important reference for predicting fault-fracture units in similar regions.