This　paper　proposes　a　model　for　the　electromagnetic　performance　of　the　dual　air-gap　liquid-cooled　eddy　current　retarder　(DAL-ECR)　considering　the　transient　permeability.　First,　the　structure　and　working　principle　of　the　DAL-ECR　are　introduced.　Next,　the　analysis　model　of　the　static　air-gap　flux　density　considering　the　flux　leakage　and　end　effect　is　established　based　on　the　piecewise　function　method　and　the　magnetic　equivalent　circuit　(MEC).　Then,　based　on　the　skin　effect　of　the　electromagnetic　field　in　the　retarder,　an　iterative　method　for　solving　the　transient　permeability　of　the　stator　is　proposed.　According　to　Faraday’s　and　Ampere’s　laws,　the　analysis　model　of　the　static　air-gap　flux　density,　and　the　transient　permeability,　the　analysis　model　of　the　transient　air-gap　flux　density　is　established.　The　braking　torque　of　the　DAL-ECR　is　then　calculated　while　taking　the　actual　path　of　the　eddy　current　and　the　skin　effect　on　the　permeability　of　the　stator　into　consideration.　Finally,　the　calculation　accuracy　of　the　model　was　verified　by　the　finite　element　method　(FEM)　and　the　bench　test.　©　2023　by　the　authors.