In this paper, the DAB topology with T-type three-level structure is taken as the research object. A multi-mode optimized modulation strategy is proposed to achieve the power factor correction. For the different operating modes of the three-level DAB, six operating modes are selected and their power transmission characteristics are summarized. The control strategy uses three modes to achieve seamless transition between modes with the goal of optimizing the backflow power. The experimental results demonstrate the feasibility of the proposed T-type three-level converter topology and multi-mode optimized strategy.