The　transformer　winding　deformation　and　the　insulation　damage　will　occur　under　the　impact　of　huge　electromagnetic　forces　caused　by　the　short　circuit　faults.　In　this　paper,　the　electromagnetic-mechanical　(E-M)　field　coupling　3D　FE　model　was　used　for　analyzing　the　transient　characteristics　of　power　transformer　under　short　circuit　faults.　Considering　the　process　of　the　transformer　winding　suffering　short　circuit　current　is　a　complicated　multi-field　coupling　problem,　this　paper　explores　the　inter-relationship　between　the　short　circuit　fault　topology,　electromagnetic　field　and　the　mechanical　field.　Both　the　mathematical　model　of　each　field　involved　and　the　E-M　field　coupling　model　have　been　built.　By　the　use　of　3D　FEM,　the　transient　characteristics　such　as　the　electromagnetic　forces,　stress　distribution　and　displacement　of　the　transformer　model　have　been　calculated　and　simulated.　Additionally,　by　analyzing　the　results　from　the　simulation　example,　the　radial　and　axial　forces　characteristics　and　the　structure　design　suggestion　for　the　winding　have　been　obtained　and　proposed.　©　2019　IEEE.