As　an　auxiliary　brake　element,　the　eddy　current　brake　is　widely　used　to　ensure　safe　driving　in　heavy　vehicles　due　to　its　noncontact　braking　characteristics.　It　is　important　to　increase　the　power　density　of　the　eddy　current　brake　and　suppress　the　thermal　derating　of　its　braking　performance.　According　to　the　principle　of　the　eddy　current　braking　and　current　skin　effect,　a　decline　in　temperature　can　greatly　increase　the　eddy　current　density　of　the　low-frequency　electromagnetic　device.　In　this　paper,　a　new　heat　dissipation　method　is　proposed　to　cool　the　heating　surface　of　the　eddy　current　brake　directly.　The　electromagnetic　field　model　and　the　flow-heat　coupling　model　are　established　to　predict　and　analyze　the　steady-state　temperature　distribution　and　braking　torque.　A　new　type　of　internal　liquid　cooling　eddy　current　brake　prototype　was　manufactured　for　a　bench　test.　The　experimental　data　prove　that　the　computational　model　is　effective.　The　calculation　results　show　that　the　new　internal　liquid　cooling　eddy　current　brake　has　improved　heat　dissipation　advantages.