Mixed　plastic　waste　treatment　has　long　been　a　significant　challenge　due　to　complex　composition　and　sorting　costs.　In　this　study,　we　have　achieved　a　breakthrough　in　converting　mixed　plastic　wastes　into　a　single　chemical　product　using　our　innovative　single-atom　catalysts　for　the　first　time.　The　single-atom　Ru　catalyst　can　convert　similar　to　90%　of　real　mixed　plastic　wastes　into　methane　products　(selectivity　＞99%).　The　unique　electronic　structure　of　Ru　sites　regulates　the　adsorption　energy　of　mixed　plastic　intermediates,　leading　to　rapid　decomposition　of　mixed　plastics　and　superior　cycle　stability　compared　to　traditional　nanocatalysts.　The　global　warming　potential　of　the　entire　process　was　evaluated.　Our　proposed　carbon-reducing　process　utilizing　single-atom　catalysts　launches　a　new　era　of　mixed　plastic　waste　valorization.