Flue　gas　desulfurization　facilities　produce　flue　gas　desulfurization　ash　(FGDA),　which　has　ecological　and　economic　benefits.　In　this　article,　we　explored　the　possibility　and　impact　of　using　FGDA　as　the　sole　reinforcing　filler　to　mechanically　improve　epoxidized　natural　rubber　(ENR).　The　influence　on　the　properties　of　the　composites　was　examined.　FGDA　exhibits　good　interfacial　interaction　and　compatibility　with　ENR,　which　improves　the　mechanical　properties　of　ENR.　When　15　phr　FGDA　was　added,　the　tensile　strength　of　the　composites　increased　by　approximately　41.4%　compared　with　that　of　pure　ENR.　This　work　demonstrates　the　possibility　of　using　FGDA　as　an　effective　and　sole　reinforcing　material　to　enhance　the　properties　of　rubber　materials.　Highlights:　FGDA　improves　the　mechanical　properties　of　ENR　as　a　sole　reinforcing　filler.　FGDA　reacts　with　ENR　during　vulcanization,　enhancing　compatibility.　Adding　15　phr　FGDA　to　ENR　increases　the　tensile　strength　by　41.4%.　©　2023　Society　of　Plastics　Engineers.