The dual-active-bridge converter was attracted many focuses in the last few decades and has been adopted as the critical topology for the isolated DC-DC converter gradually. Because of many merits like galvanic isolation, a wide range of zero-voltage-switching, and high voltage conversion ratio, to name a few. The control strategies for the DAB are varies with a wide range aspect. Thus, this paper aims to review the control strategy in terms of the dc-bias current elimination in the transient-state of a single-phase DAB DC-DC converter. The phase-shift ratios patterns are introduced before relevant control strategies for dc-bias current elimination, which can be summarized as the piecewise linear optimization. Finally, the straightforward transient control which can be utilized in different phase-shift controls is analyzed as a universal solution.