A　variable　inductance　(VI)　structure　for　dual　active　bridge　(DAB)　DC-DC　converter　based　on　controllable　switches　is　proposed　in　this　work.　First,　this　paper　analyzes　the　difference　in　the　efficiency　of　DAB　converter　in　different　power　ranges,　and　proposes　a　method　to　make　the　converter　work　continuously　in　high　efficient　power　range　by　changing　the　value　of　the　inductor.　Secondly,　the　VI　structure　is　proposed　to　connect　controllable　switches　and　inductors　of　different　values　in　series　or　parallel　with　each　other,　which　is　simple　in　structure　and　can　achieve　stable　operation.　Based　on　this　VI　structure,　a　control　method　combining　the　existing　phase　shift　modulation　optimization　scheme　is　proposed.　Finally,　the　proposed　method　is　validated　on　the　MATLAB/Simulink　platform　to　efficiently　reduce　the　reactive　power　of　the　existing　phase　shift　modulation　optimization　schemes,　which　is　practicable　and　superior.　©　2023　IEEE.