Current　handling　capability　of　parallel　PCB　winding　in　planar　transformer　can　be　effectively　enhanced　by　winding　loss　model　and　relative　design　tool.　The　analytical　eddy　current　loss　model　of　PCB　winding　with　arbitrary　connections　for　both　rectangular　and　spiral　types　is　built　based　on　eddy　current　field　equations　and　loop　voltage　balance.　And　furthermore,　a　processing　method　with　distinct　form　and　systematic　programming　algorithm　are　also　proposed　with　superposition　principle　to　code　the　loss　model　into　software　with　friendly　human-machine　interface.　Experiments　verified　the　loss　model　and　the　algorithm.　And　the　software　was　also　ensured　by　systematic　verification　and　experiments.　The　software　provides　a　powerful　tool　for　the　PCB　winding　design　with　arbitrary　parallel　connections.