Selective　adsorption　of　alpha,beta-unsaturated　aldehydes　(alpha,beta-UALs)　is　a　prerequisite　for　the　hydrogenation　of　alpha,beta-UALs　to　high-value　unsaturated　alcohols,　but　a　quantitative　description　of　the　interactions　between　the　C=C/C=O　bond　of　alpha,beta-UALs　and　the　catalysts　is　still　lacking.　Herein,　based　on　comprehensive　density　functional　theory　calculations,　we　developed　a　descriptor　that　combines　the　near-frontier　molecular　orbitals　of　the　C=C/C=O　bonds　of　alpha,beta-UALs　with　the　fundamental　physical　properties　of　single-atom　catalysts　(SACs)　and　considers　the　inner/outer　coordination　environment.　All　of　the　parameters　used　in　this　descriptor　are　easily　accessible　and　interpretable,　enabling　an　efficient　assessment　of　the　selectivity　of　SACs　for　the　C=C/C=O　bonds　of　alpha,beta-UALs.