Marine　electromagnetic　transmitter　transmits　large　power　variable　frequency　electromagnetic　wave　to　the　seabed　so　as　to　obtain　the　submarine　structure　and　mineral　resources.　The　mathematical　model　of　controlled　source　circuit　needs　to　be　established　to　realize　closed　loop　control　for　increasing　control　precision　and　output　transient　performance　of　the　electromagnetic　wave.　The　operation　process　of　controlled　circuit　is　analyzed　in　continuous　current　mode,　two　equivalent　switching　states　of　controlled　source　circuit　are　obtained　through　the　analysis　of　the　different　states　of　the　switch　in　a　switching　period.　A　small　signal　equivalent　model　of　the　system　is　established　using　small　ripple　approximation.　For　high　output　voltage　fluctuation　problem　in　single　loop　control,　double　loop　control　strategy　of　voltage　loop　and　current　loop　is　designed.　The　simulation　and　experimental　results　show　that,　the　system　has　the　advantages　of　fast　transient　response　speed　and　good　regulation　performance.　©　Haijun　et　al.;　Licensee　Bentham　Open.