Although　strain　engineering　is　effective　in　boosting　the　activities　of　noble　metal　catalysts,　it　remains　desirable　to　construct　fully　strained　catalysts　to　push　the　activity　to　even　higher　levels.　Herein,　we　report　a　novel　route　to　strong　lattice　strains　of　a　Pd-based　catalyst　by　radial　growth　of　a　Pd-rich　phase　on　Au-Ag　alloy　nanowires　that　are　no　thicker　than　1.5　nm.　It　creates　not　only　tensile　strains　in　the　Pd-rich　sheath　due　to　the　core-sheath　lattice　mismatch　but　also　distortion　and　twinning　of　the　lattice,　producing　nonhomogeneous　local　strains　as　hotspots　for　the　catalysis.　Toward　the　electrochemical　oxidation　of　biomass-derived　alcohols　including　ethanol,　ethylene　glycol,　and　glycerol,　the　highly　strained　nanowires　outperformed　their　less　strained　counterparts　and　reached　up　to　13.6,　18.2,　and　11.1　A　mgPd-1,　respectively.　This　strain　engineering　strategy　may　open　new　avenues　to　highly　efficient　catalysts　for　direct　alcohol　fuel　cells　and　many　other　applications.　©　2021　American　Chemical　Society.　All　rights　reserved.