Abstract: The fourth member of the Funing Formation (referred to as Fu 4 Member) in the Gaoyou sag of the Subei Basin is rich in shale oil resources. However, its exploration and development are still in the initial stage, making seismic sweet-spot prediction imperative to clarify the exploration potential and development direction. We define total organic carbon (TOC) content, free hydrocarbon (S1), porosity, brittle mineral content, pressure coefficient, and in-situ stress as the key parameters for predicting geologic-engineering sweet spots. Based on sweet spot characteristics, the relationships between key geologic-engineering and elastic parameters are established through petrophysical analysis. Using noise-resistant elastic inversion with full-gather quadratic fitting, a high-precision geophysical parameter prediction workflow is constructed, enabling the quantitative prediction and comprehensive evaluation of geologic-engineering sweet spots. Research results indicate an area of 84.35 km² for high-graded sweet spots in the study region. Top reservoir properties occur in the Fanchuan sub-sag, with TOC content up to 1.9%, S1 of 4.6 mg/g, porosity of 8%, brittle mineral content of 85%, pressure coefficient above 1.6, and stress difference ratio below 0.2. These prediction techniques, validated by the high-yield commercial oil flow from Y108, a horizontal well deployed in the optimized sweet-spot area, provide technical support for shale oil exploration and development in the region.