This　paper　presents　a　new　variable-frequency　phase-shift　control　method　to　improve　the　conversion　efficiency　for　a　high-power　wide-range　converter　based　on　a　phase-shifted　full-bridge　(PSFB)　converter.　The　proposed　converter　can　adjust　the　switching-frequency　according　to　the　load　power　to　make　the　input　impedance　be　inductive.　The　main　switches　of　the　converter　can　achieve　zero　voltage　switching　(ZVS)　over　a　wide　load　range　(500　W-50　kW)　without　any　auxiliary　circuit.　The　maximum　switching-frequency　of　high-power　insulated　gate　bipolar　transistor　(IGBT)　is　determined　by　analyzing　the　influence　of　collector　current　on　IGBT　switching　time.　The　necessary　condition　for　the　proposed　converter　to　realize　ZVS　is　given　according　to　the　steady-state　model　of　the　full-bridge　converter.　This　paper　analyzed　the　influence　of　voltage,　current　and　temperature　on　the　switching　time　of　high-power　IGBT　in　detail,　and　obtained　the　relationship　between　the　load　current　and　the　dead　time　of　high-power　IGBT.　The　optimal　switching-frequency　under　different　loads　was　determined　by　establishing　a　switching-frequency　loss　model　of　the　proposed　converter.　A　50　kW　prototype　of　the　proposed　converter　was　developed　and　the　experimental　and　simulation　results　verify　the　effectiveness　and　efficiency　of　the　proposed　method.