Magnetic-coupling　excitation　system　is　one　of　the　research　highlights　in　the　field　of　brushless　Electrically　Excited　Synchronous　Motor　(EESM),　which　contains　the　primary　energy　emission　device　and　a　secondary　receiving　device　that　rotates　synchronously　with　the　motor　rotor.　Primary-side　control　estimation　is　widely　applied　in　Wireless　Power　Transmission　(WPT)　system　to　detect　the　output　current　of　the　secondary　device　to　reduce　the　weight　of　rotor　and　achieve　the　merit　of　communication-free.　A　magnetizing　current　estimation　method　based　on　the　Kalman　filter　algorithm　is　proposed　for　a　novel　system　combined　with　EESM　and　WPT.　The　proposed　method　adopts　the　Kalman　filter　algorithm　to　the　magnetizing　current　estimation　model,　which　eliminates　the　higher-order　harmonics　in　the　sampling　of　inverter　current　and　transmitting　coil　current.　In　addition,　the　output　current　control　is　achieved　by　applying　the　PI　controller.　The　simulation　result　of　proposed　system　in　Matlab/Simulink　proves　the　enhancement　of　proposed　method　on　the　accuracy,　the　transient　response　speed　and　the　tracking　performance　of　magnetizing　current　estimation.