Here,　the　mixed　metal　nodes　MOFs,　Pd/MIL-100(FeaCub),　were　constructed　as　photocatalysts　for　hydrogenation　of　alpha,beta-unsaturated　aldehyde　(UAL)　under　visible　light.　1　wt%　Pd/MIL-100(Fe0.81Cu0.19)　can　convert　a　range　of　UAL　to　saturated　aldehydes　(SAL)　with　a　high　efficiency　(approximate　to　100　%)　and　selectivity　(approximate　to　98　%).　The　results　of　XPS　and　in　situ　DRIFTS　reveal　that　UAL　can　be　selectively　activated　via　a　coordination　of　-C--C-　on　Cu2+　sites,　determining　the　high　selectivity　of　the　photocatalytic　reaction.　The　mixed　metal　nodes　and　Pd　clusters　can　improve　the　transformation　and　separation　of　photogenerated　electrons-holes.　EPR　result　suggests　that　photogenerated　carriers　can　facilitate　the　generation　of　H　center　dot　on　Pd/MIL-100(Fe0.81Cu0.19),　enhancing　the　catalytic　activity.　A　possible　mechanism　is　proposed　for　elucidating　the　catalytic　processes　at　the　molecular　level.　This　work　provides　a　valuable　strategy　for　tailoring　the　selectivity　of　photocatalytic　hydrogenation　via　selective　coordination　activation.