Stability　is　fundamental　to　ensure　the　operation　of　control　system,　but　optimality　is　the　ultimate　goal　to　achieve　the　maximum　performance.　This　paper　investigates　an　event-triggered　pinning　optimal　consensus　control　for　switched　multi-agent　system　(SMAS)　via　a　switched　adaptive　dynamic　programming　(ADP)　method.　The　technical　contribution　mainly　lies　in　two　aspects.　On　the　one　hand,　in　order　to　optimize　the　control　performance　and　ensure　the　consensus,　the　switched　local　value　function　(SLVF)　and　the　minimum-error　switching　law　are　constructed.　Based　on　SLVF,　an　algorithm　of　switched　ADP　policy　iteration　is　proposed,　and　its　convergence　and　optimality　are　proved.　On　the　other　hand,　considering　that　it　is　impractical　to　install　a　controller　for　each　agent　in　reality,　a　pinning　strategy　is　developed　to　guide　the　setting　of　the　ADP　controller,　which　can　reduce　the　waste　of　control　resources.　A　new　condition　is　constructed　to　determine　the　minimum　number　of　controlled　vertices　of　the　SMAS.　Lastly,　a　numerical　example　is　given　to　verify　the　effectiveness　of　the　proposed　method.　©　2022　Elsevier　Ltd