During the exploration and development of deep salt mineral resources, the frequent technical challenge of drilling fluid loss features complex formation mechanisms and significant sealing difficulties. Under the combined effects of tectonic stress, groundwater dissolution, and engineering disturbances, reservoirs and near-wellbore zones are prone to developing multi-scale fracture networks and even dissolution cavities, forming a multi-channel seepage system. Taking Well A in Hebei brine extraction project as an example: leakage occurred at 2594m depth, which evolved into an unrecoverable loss scenario with simultaneous influx and leakage in the same stratum at 2598m, severely impacting drilling efficiency. To address this leakage issue, this study employs crosslinked cement slurry composite sealing technology. Leveraging the excellent water isolation properties and controllable crosslinking time of the gel, a network-like separation layer was formed to provide effective support for subsequent cement slurry consolidation. After two sealing operations, the returned drilling fluids reached approximately 80% of the normal circulation volume. This composite technology effectively resolves the adaptability limitations of traditional single sealing materials and offers a novel solution for managing severe leakage in deep drilling engineering.