The traditional single-mode cascaded architecture suffers from adaptability deficiencies under operational condition variations such as sudden load changes or input voltage fluctuations due to its fixed structure, leading to significant efficiency degradation (with typical losses reaching 12–15% under standard operating conditions). To address this issue, this paper proposes a novel multi-mode cascaded dual active bridge (DAB) DC-DC converter topology, and conducts systematic research on advanced control methods and mode-switching strategies. This approach achieves adaptive regulation under environmental disturbances while maintaining the optimal efficiency of a single module. Furthermore, this topology integrates a dual closed-loop control system with current optimization strategies to ensure voltage balancing across each module and enhance system dynamic response. Combined with an extended phase-shift modulation strategy, it effectively optimizes inductor current stress, reducing power losses and thermal rise. Finally, simulation results verify the validity of the proposed solution.