Direct　aluminium-stainless　steel　joints　are　difficult　to　create　by　the　vaporized　foil　actuator　welding　(VFAW)　method　because　brittle　intermetallic　compounds　(IMCs)　tend　to　form　along　the　interface.　The　use　of　an　interlayer　as　a　transition　layer　between　the　two　materials　with　vast　difference　in　hardness　and　ductility　was　proposed　as　a　solution　to　reduce　the　formation　of　the　IMCs.　In　this　work,　VFAW　was　used　to　successfully　weld　sheet　aluminium　alloy　5A06　to　stainless　steel　321　with　a　3003　aluminium　alloy　interlayer.　Input　energy　levels　of　6　kJ,　8　kJ,　10　kJ,　and　12　kJ　were　used　and　as　a　trend,　higher　energy　inputs　resulted　in　higher　impact　velocities,　larger　weld　area,　and　better　mechanical　properties.　In　lap-shear　and　peel　testing,　all　samples　failed　at　the　interface　of　the　interlayer　and　target.　At　10　kJ　energy　input,　flyer　velocities　up　to　935　m/s,　lap-shear　peak　load　of　44　kN,　and　peel　load　of　2.15　kN　were　achieved.　Microstructure　characterization　and　element　distribution　were　performed,　and　the　results　show　a　wavy　pattern　created　between　the　flyer　and　interlayer　which　have　similar　properties,　and　the　interface　between　the　interlayer　and　target　was　dominated　by　element　diffusion　and　IMCs　identified　mainly　as　FeAl3　and　FeAl.　The　results　demonstrate　VFAW　is　a　suitable　joining　method　for　dissimilar　metals　such　as　aluminium　alloy　and　stainless　steel,　which　has　a　broad　and　significant　application　prospect　in　aerospace　and　chemical　industry.