Aqueous　micellar　catalysis　has　become　recognized　as　an　efficient,　green　and　sustainable　technology,　yet　is　still　challenging　to　improve　the　catalytic　selectivity　by　manipulating　the　microenvironment　of　bimetallic　nanoalloys.　In　this　work,　we　present　a　water-based　micelle-bimetal　strategy　to　regulate　effectively　the　selective　hydrogenation　of　alpha,(3-unsaturated　aldehydes.　This　strategy　employed　surfactant　GluM　to　stabilize　PtCu　bimetallic　alloys　and　enrich　the　substrate　to　reinforce　the　contact　with　NPs.　Importantly,　the　steric　effect　created　by　surfactant　GluM　can　modulate　the　adsorption　mode　of　alpha,(3-unsaturated　aldehydes　on　the　alloy　surface　from　planar　configuration　to　linear　configuration.　The　remarkable　conversion　(up　to　98.5　%)　and　selectivity　(up　to　94.6　%)　for　the　hydrogenation　of　alpha,(3-unsaturated　aldehydes　to　unsaturated　alcohols　were　achieved,　attributed　to　a　synergy　of　favorable　factors,　such　as　alloy　effect,　multifunctionality　of　GluM　and　auxiliary　effect　of　H2O.　This　work　not　only　highlights　the　important　role　of　the　specific　microenvironment　surrounding　the　bimetal　alloys　in　regulating　the　catalytic　selectivity,　but　also　provides　a　novel　reference　for　improving　catalytic　selectivity　in　aqueous　micelles.