We　propose　a　novel　dual　air-gaps　and　liquid-cooled　eddy　current　retarder　(ECR)　based　upon　observing　the　(1)　heat　fade　of　the　continuous　braking　and　(2)　large　rotor　weight　of　the　traditional　ECR　for　heavy　vehicles.　The　new　ECR　maintains　a　low　working　temperature　because　of　the　liquid　cooling　stator　structure.　The　eddy　current　distribution　and　braking　torque　characteristic　curves　are　obtained　by　finite　element　method　(FEM).　Combining　with　3-D　FEM,　Kriging　approximation　model　is　employed　to　optimize　the　structural　parameters　of　rotor　tooth.　Based　on　the　optimization　method,　the　number　of　rotor　teeth　is　determined　to　be　12.　The　braking　torque　increases　by　14.8%　after　optimization　and　the　rotor　tooth　weight　decreases　by　9.5%,　which　reduces　the　adverse　influence　on　the　vehicle　transmission　system.　The　bench　test　was　carried　out　to　verify　the　optimized　calculation　results　and　the　braking　torque　can　be　stepless　controlled　by　adjusting　the　excitation　current.　Compared　with　traditional　ECR,　the　dual　air-gaps　and　liquid-cooled　ECR　has　better　continuous　braking　performance　and　is　more　suitable　for　heavy　vehicle　auxiliary　braking.