Existing　DC-DC　converter　has　some　shortcomings,　such　as　low　power,　low　efficiency,　and　poor　load　adaptability.　For　which　a　novel　soft　switching　three-level　DC-DC　converter　is　proposed,　a　step-down　winding　in　secondary　side　of　high-frequency　transformer　in　series　with　commutation　inductance　is　added　to　ensure　the　devices　soft　switching　in　the　full　power　scope　using　asymmetrical　phase-shift　PWM　control.　The　operation　process　and　characteristics　of　the　circuit　are　analyzed,　and　a　prototype　is　completed.　Experimental　results　verify　the　proposed　DC-DC　converter　with　high　input　voltage,　wide　ZVS　range,　and　high　efficiency.