To address the issues of large modeling errors in fundamental harmonic analysis, limited voltage gain regulation capability under variable frequency control, and insufficient disturbance rejection capability of bidirectional CLLC resonant converters, an optimized dual-phase-shift active disturbance rejection control strategy based on time-domain analysis is proposed. Through the construction of a state-space model, the design of an extended state observer, and a double closed-loop controller, precise system control and disturbance suppression are achieved. First, the state equations of the converter are established using the time-domain analysis method, and the voltage gain expression under off-resonance conditions is derived. Second, dual-phase-shift modulation is adopted to broaden the voltage gain regulation range by adjusting the inner and outer phase-shift angles within the soft-switching constraints. Then, a double closed-loop control system consisting of an outer-loop voltage active disturbance rejection controller and an inner-loop current PID (proportional-integral-derivative) controller is constructed. An extended state observer is adopted to estimate and compensate internal and external disturbances in real time, thereby strengthening the system's stability and dynamic response capability. Finally, a simulation system is developed in MATLAB/Simulink to verify the proposed control approach. The results indicate that the proposed method effectively enhances gain accuracy, broadens the regulation range, and significantly improves dynamic response capability under wide voltage variation and load disturbance conditions.