Abstract: How to identify the core zone of a fracture-cavity unit is crucial to the characterization of fracture-cavity reservoirs. Owing to the complex overlapping relationships among pores, cracks, cavities, fluids, and faults, seismic facies analysis itself proves inadequate for the accurate effective interpretation of fracture-cavity units. Moreover, traditional attributes such as coherence, curvature, and maximum likelihood no longer meet the precision requirements of exploration and development activities. This study proposes a novel methodology for characterizing complex fracture-cavity reservoirs in the Yueman area, the Tarim Basin. Through detailed seismic interpretation to determine the top and bottom boundaries of the reservoir, the target horizons are extracted from the original seismic data to form a stratal slice volume. Spatial-wavenumber domain filtering is then used to remove the stratigraphic background of the stratal slice volume. The first eigenvalue of the gradient structure tensor is extracted from the fracture-cavity unit, and energy ridge tracking is performed based on the threshold and amplitude constraints to identify the core zone of the fracture-cavity unit. The identification results integrated with the stratal slice volume are finally embedded into the original seismic data, yielding a final data volume for fracture-cavity characterization. Application results from the W5 well field demonstrate a high degree of consistency with well and seismic data and the feasibility of this method. Three favorable targets successfully predicted in the W2 well field further demonstrate its effectiveness in characterizing complex fracture-cavity units and the significant potential for broader application.