Abstract: In order to solve the problem of excessive backflow power to high conduction loss in conventional dual active bridge(DAB) converters, a dual bridge resonant DC-DC converter with CLC-type resonant network is proposed in this paper. Based on the original circuit, a resonant network was introduced to study CLC series resonant DC-DC converter, which can reduce component cost and the size of the resonant network. Combined with the dual in-phase modulation(DIM), the converter can achieve zero backflow power and unity power factor(UPF) operation, greatly reducing the conduction losses and improving efficiency. The equivalent circuit model of the CLC-DAB DC-DC converter was established by multiple harmonics approximation(MHA) analysis, and the expressions of power transmission and output current of the converter were derived. The operation principle and control method of the system was validated through PSIM. The efficiency of the system performance was validated by the experimental results.