Abstract: Dual-active bridge (DAB) DC-DC converter can achieve better current characteristics and transmission efficiency while eliminating bilateral backflow power under the traditional cooperative triple-phase-shift (CTPS) control. However, the influences of dead time on voltage, current and optimization effect are not considered in the above optimization algorithm. Therefore, through detailed analysis on influences of dead time on DAB voltage and current waveform and backflow power optimization in different power segments, the paper derives a new shift ratio calculation formula containing dead time based on volt-second balance principle and establishes a transmission power model and power critical point. On the basis of this, an improved cooperative triple-phase-shift (ICTPS) control strategy is proposed to suppress the influences of dead time in different power segments. Finally, the comparative experiments are carried out on the experimental prototype. The corresponding experimental results verify the validity of the theoretical analysis on dead time influences and the inhibitory effect of the effectiveness on suppression of dead time influence with the proposed ICTPS control strategy.