Rationally　constructing　nanoalloys　achieving　the　synergy　of　multiple　interactions　among　different　constituents　could　substantially　enhance　the　electrocatalytic　performance　of　an　active　metal　for　a　given　chemical　reaction.　In　this　context,　we　design　and　synthesize　well-controlled　ternary　CuZnPd　alloy　nanoparticles,　in　which　the　Cu　atoms　modify　the　electronic　configuration　of　Pd　atoms　through　the　ligand　effect　or　the　lattice　strain　effect,　while　the　Zn　atoms　clean　their　neighboring　Pd　sites　through　a　bifunctional　mechanism,　and　the　synergy　of　these　two　benefits　endows　the　ternary　CuZnPd　alloy　nanoparticles　with　exceptional　electrocatalysis　for　a　room-temperature　ethanol　oxidation　reaction　(EOR).　In　specific,　at　an　appropriate　1/1/1　molar　ratio　for　Cu/Zn/Pd,　the　as-prepared　ternary　CuZnPd　alloy　nanoparticles　exhibit　both　the　highest　specific　activity　and　mass　activity　of　17.3　mA　cm(-2)　and　11.8　A　mg(-1),　respectively,　which　outperform　those　of　their　CuPd,　ZnPd　alloy　counterparts　and　the　commercial　Pd/C　catalyst,　as　well　as　the　majority　of　recently　reported　Pd-based　catalysts.　Density　functional　theory　calculations　verify　that　the　key　CO*　and　CH3CHO*　intermediates　generated　during　the　EOR　have　the　lowest　adsorption　energy　on　the　ternary　CuZnPd　alloy　nanoparticles,　which　is　responsible　for　their　boosted　EOR　electrocatalysis.