Abstract: To accurately predict the morphology, stability, and sealing capacity of irregular salt caverns and support their application in compressed air energy storage, this study establishes a comprehensive geological and geophysical evaluation workflow for salt cavern storage. In this workflow, the tectonic stability of the salt cavern area is first assessed through detailed structural interpretation, followed by the prediction of salt rock and interbed distribution using target-oriented probability inversion. Based on seismic forward modeling, multi-attribute analysis and 3D geological body characterization are performed to quantitatively predict salt cavern morphology and effective volume. Finally, microscopic characterization of salt cavern core samples is conducted to verify the sealing capacity of the cavern roof. Application of this workflow to the abandoned salt cavern in the Wenkou sag indicates that almost no major faults are developed within a 2 km radius of the salt caverns, the total salt layer thickness exceeds 60 m, and the salt rock accounts for approximately 50% of the salt-bearing formation. Among these, salt layers 1 to 5 are stably developed throughout the area, interbedded with gypsum-salt layers, with both the roof and floor consisting of compacted lithologies. A seismic facies model for the salt caverns is established based on forward modeling. The model shows an upward-convex, strong-amplitude reflection at the cavern top and a downward-concave, weak-amplitude reflection at the bottom, with seismic event discontinuities on both flanks. Four sensitive attributes—instantaneous amplitude, texture, edge detection, and coherence energy gradient—are preliminarily selected for salt cavern characterization. The results reveal that the salt caverns in Wells 1, 4, and 5 are relatively isolated, while connecting channels exist between the salt caverns in Wells 2 and 3. The edge detection attribute demonstrates the best characterization performance. On this basis, the "threshold segmentation method" is used to delineate the 3D morphology of the salt caverns. The predicted volume aligns with the salt extraction-converted volume and well data, with an error rate of only 0.76%. Core samples from the salt caverns further verify the strong sealing capacity of salt cavern roofs through tests of microscopic structure, porosity, permeability, breakthrough pressure, and diffusion coefficient. In summary, the salt caverns in the study area exhibit a stable tectonic setting, considerable reservoir space, and strong sealing capacity, satisfying the geological requirements for the construction of compressed air energy storage facilities.