Existing　research　on　human　channel　modeling　of　galvanic　coupling　intra-body　communication　(IBC)　is　primarily　focused　on　the　human　body　itself.　Although　galvanic　coupling　IBC　is　less　disturbed　by　external　influences　during　signal　transmission,　there　are　inevitable　factors　in　real　measurement　scenarios　such　as　the　parasitic　impedance　of　electrodes,　impedance　matching　of　the　transceiver,　etc.　which　might　lead　to　deviations　between　the　human　model　and　the　in　vivo　measurements.　This　paper　proposes　a　field-circuit　finite　element　method　(FEM)　model　of　galvanic　coupling　IBC　in　a　real　measurement　environment　to　estimate　the　human　channel　gain.　First　an　anisotropic　concentric　cylinder　model　of　the　electric　field　intra-body　communication　for　human　limbs　was　developed　based　on　the　galvanic　method.　Then　the　electric　field　model　was　combined　with　several　impedance　elements,　which　were　equivalent　in　terms　of　parasitic　impedance　of　the　electrodes,　input　and　output　impedance　of　the　transceiver,　establishing　a　field-circuit　FEM　model.　The　results　indicated　that　a　circuit　module　equivalent　to　external　factors　can　be　added　to　the　field-circuit　model,　which　makes　this　model　more　complete,　and　the　estimations　based　on　the　proposed　field-circuit　are　in　better　agreement　with　the　corresponding　measurement　results.