Two　dimensional　transition　metal　carbides　(MXenes)　have　attracted　significant　interest　due　to　their　unique　layer　structure,　chemical　diversity　and　superior　physiochemical　performances.　However,　most　studies　have　focused　on　Ti3C2Tx,　and　the　synthesis　process　and　photothermal　conversion　capability　of　other　MXenes　remain　unclear.　In　this　work,　we　have　systematically　investigated　the　exfoliation　behavior　of　six　different　MXenes,　including　monotransition-metal　(Ti3C2Tx,　V2CTx,　and　Nb2CTx)　and　double-transition-metal　(TiVCTx,　TiNbCTx,　and　NbVCTx)　MXenes　derived　from　MAX　phases,　integrated　with　their　photothermal　conversion　performance　by　combining　experimental　and　theoretical　studies.　The　phase,　morphology,　composition　and　surface　groups　of　the　different　MXenes　have　been　analyzed　using　XRD,　SEM,　XPS,　and　HRTEM　techniques.　Our　results　indicate　a　systematic　variation　in　etching　difficulty　from　difficult　to　easy,　as　Nb2AlC　＞　NbVAlC　＞　V2AlC　＞　TiNbAlC　＞　TiVAlC　＞　Ti3AlC2,　which　correlates　with　the　chemical　composition　and　etching　duration.　Furthermore,　the　exfoliation　factor　m　from　density　functional　theory　calculations　reveals　that　the　bond　energies　of　M-A　bonds　are　much　weaker　than　M-X　bonds　in　MAX　phases,　which　agrees　well　with　the　experimental　results.　Interestingly　that,　all　the　obtained　MXenes　exhibit　remarkable　photothermal　conversion　performance　with　fast　response,　where　the　MXenes　beyond　Ti3C2Tx,　such　as　V2CTx,　NbVCTx,　Nb2CTx,　TiVCTx,　and　TiNbCTx,　display　higher　saturation　temperature　of　95,　88,　81,　78,　and　71　degrees　C,　respectively,　than　that　of　Ti3C2Tx　(65　degrees　C).　These　findings　could　potentially　facilitate　the　efficient　design　and　development　of　diverse　MXene　materials　with　outstanding　photothermal　conversion　performance　for　applications　in　wearable　devices,　biomedical　technology　and　solar　water　desalination.