In　this　paper,　the　sensitivity　of　switching-off　voltage　spikes　of　SiC　MOSFET　and　Si　IGBT　to　stray　inductance　at　the　same　voltage　and　current　levels　is　compared　and　analyzed.　The　influence　of　the　geometric　structure　of　simple　stacked　busbar　on　its　stray　inductance　is　analyzed　and　the　general　guiding　principle　of　busbar　design　is　given.　Aimed　at　the　three-level　circuit　topology　involved　in　this　project,　based　on　the　analysis　of　its　working　principle　and　commutation　circuit,　the　stray　inductance　network　of　stacked　busbar　is　successfully　extracted　with　the　help　of　finite　element　simulation　software　ANSYS　Q3D,　and　the　idea　of　optimizing　stray　inductance　of　maximum　commutation　circuit　is　putted　forward.　A　set　of　three-level　AC-DC-AC　power　electronic　device　is　designed,　and　a　series　of　iterative　optimization　design　and　optimization　results　analysis　of　the　busbar　of　the　device　are　made.　©　2019　Published　under　licence　by　IOP　Publishing　Ltd.