Addressing the lack of clarity regarding spontaneous imbibition displacement mechanisms and production management strategies for shale oil in the Cangdong Sag, a model was established that considered the "synergy of imbibition, flowback, and productivity". The model was designed to dynamically reflect the mutual constraints and synergies between spontaneous imbibition displacement and engineering parameters such as flowback rates and soaking durations. Through comprehensive numerical simulations integrating geology and engineering across the entire lifecycle, the spontaneous imbibition displacement patterns and optimal flowback regimes for the C1 and C3 sweet spots in the Kong-2 Member, which served as the main development interval in the Cangdong Sag, were elucidated. The results indicate that spontaneous imbibition displacement continues to occur during the flowback process. The optimal soaking durations for the C1 and C3 sweet spots are determined to be between 37 and 42 days, with a reasonable flowback rate ranging from 20 to 40 tons per day. The research findings provide a theoretical foundation for studies on spontaneous imbibition mechanisms and reasonable production management strategies for deep shale oil and gas reservoirs.