The　purpose　of　this　study　was　to　explore　the　potential　of　the　development　and　application　of　Paecilomyces　hepiali,　a　fungus　with　edible　and　medicinal　value,　as　a　foodborne　antioxidant　and　anti-aging　agent.　Its　n-butanol　extract　(PHE)　from　rice　cultures　was　selected　for　anti-aging　experiment　because　of　significant　free　radical　scavenging　activity　in　vitro.　In　vivo,　PHE　could　significantly　prolong　the　mean　lifespan,　50％　survival　days,　and　the　maximum　lifespan　of　Drosophila　on　a　high-fat　diet.　It　is　amazing　that　the　mean　lifespan　increased　from　19.1　days　to　32.9　days,　50％　survival　days　increased　from　15.7　days　to　34.3　days,　and　the　maximum　lifespan　extended　from　44.7　days　to　52.7　days,　when　the　high-fat　female　Drosophila　model　was　fed　with　10　μg/mL　PHE.　Further　research　showed　that　PHE　reduced　the　accumulation　of　peroxide　products　and　increased　the　activity　of　antioxidant　enzymes.　Then,　through　antioxidant　activity　tracking,　dimerumic　acid　(compound　1,　the　IC50　value　of　3.4　μg/mL　on　DPPH　free　radicals　scavenging　activity),　4,5-dihydroxy-3-methoxypentanoic　acid　(compound　2,　new　compound),　and　thymidine　(compound　3)　were　isolated　from　PHE.　It　is　worth　mentioning　that　dimerumic　acid,　the　major　antioxidant　compound　of　PHE　(content　up　to　3％),　was　discovered　in　P.　hepiali　for　the　first　time.　It　was　concluded　that　PHE　showed　excellent　anti-aging　activity　at　a　very　low　concentration　on　fat　diet-induced　high　fat　Drosophila　melanogaster,　and　dimerumic　acid　may　be　its　main　material　basis.　These　results　indicated　that　PHE　had　the　potential　to　be　developed　as　antioxidant　and　anti-aging　agent　in　the　healthcare　industry.