PCB　winding　with　parallel　connection　is　a　good　solution　to　improve　current　handling　capability　of　high-frequericy　power　planar　transformer.　However,　uneven　current　sharing　among　paralleled　PCB　layers　caused　by　circumfluent　current　imposes　severe　challenges　on　the　winding　design.　The　mechanism　and　factors　affecting　the　current　sharing　are　analyzed　deeply　and　thoroughly　with　AC　eddy　loss　model　built.　The　results　show　that　exciting　current　frequency,　PCB　trace　layout,　trace　connection　schemes,　thickness　of　traces　and　insulation　of　parallel　PCB　winding　all　have　great　effects　on　the　winding　loss.　The　design　guidelines　for　parallel　PCB　winding　and　systematic　programming　technique　for　the　loss　model　are　also　given.　Loss　model　is　verified　by　the　experiments.