The　marine　electromagnetic　transmitter　sends　high-power　variable-frequency　electromagnetic　waves　to　acquire　seabed　structure　and　distribution　law　of　mineral　resources.　The　traditional　transmitter　has　some　shortcomings,　such　as　small　power,　low　efficiency,　and　poor　load　adaptability.　In　this　article,　a　novel　transmitter　circuit　composed　of　zero　voltage　zero　current　switching　(ZVZCS)　controlled-source　circuit　is　proposed,　which　overcomes　the　limitations　of　a　zero-voltage　switching　one,　such　as　high　freewheeling　energy,　duty　ratio　loss,　and　limited　zero-voltage　switching　load　range　for　the　lagging-leg　switches.　Current　in　primary　winding　during　the　freewheeling　period　is　reduced　to　zero　by　using　a　blocking　capacitor　and　a　saturable　reactor,　realizing　zero-current　switching　turn-on　for　leading-leg　switches,　as　well　as　zero-current　switching　for　lagging-leg　switches.　Finally,　the　proposed　circuit　is　verified　by　a　200-A　marine　transmitter.