Biodegradable　plastics　such　as　polylactic　acid　(PLA)　have　been　extensively　applied　in　numerous　fields.　Although　PLA　is　degradable　in　natural　environments,　its　decomposition　postdisposal　leads　to　resource　wastage.　Herein,　we　first　employ　enzymatic　hydrolysis　to　degrade　PLA.　Subsequently,　PtPb　alloy　nanoparticles　are　synthesized　in　a　single　step　via　a　wet　chemical　method,　catalyzing　the　reformation　of　the　PLA　enzymatic　hydrolysis　products　into　higher-value　chemicals　(pyruvic　acid).　Under　conditions　of　an　oxygen　flow　rate　of　60　mL/min,　a　reaction　temperature　of　90　degrees　C,　and　a　reaction　duration　of　60　min,　the　conversion　rate　of　lactic　acid　catalytic　oxidative　dehydrogenation　to　pyruvic　acid　reaches　an　impressive　96.86%,　with　a　selectivity　of　95.69%.　Moreover,　this　catalyst　exhibits　satisfactory　stability.　Experimental　and　density　functional　theory　(DFT)　calculations　are　combined　to　ascertain　the　active　state　changes　of　PtPb　and　the　reaction　pathways　for　the　catalytic　oxidative　dehydrogenation　of　lactic　acid　to　pyruvic　acid,　as　well　as　the　free　energy　changes　of　different　catalysts　in　this　transformation.　In　this　work,　we　employ　a　simple　synthetic　strategy　to　specifically　investigate　the　impact　of　PtPb　alloy　nanoparticles　under　various　conditions　on　the　catalytic　oxidative　dehydrogenation　of　lactic　acid　to　pyruvic　acid,　offering　a　new　research　avenue　for　the　waste　treatment　and　resource　utilization　of　biodegradable　plastics　in　the　future.