Perfluorooctanoic　acid　(PFOA),　a　novel　organic　pollutant,　has　been　shown　to　be　toxic,　persistent,　bioaccumulative,　long-range　transportable,　and　globally　prevalent.　This　article　is　based　on　surface　enhanced　Raman　scattering　(SERS)　spectroscopy　analysis　technology.　The　monolayer　of　SiO2　was　prepared　by　chemical　reduction　etching　self-assembly　method　and　silver　dendrites　were　grown　on　it,　thus　forming　the　SERS　substrate　with　silver　dendrite　Metasurface　structure　with　Raman　detection　enhancement　factor　up　to　2.32　x　105.　The　prepared　silver　dendrite　Metasurface　SERS　substrate　was　applied　to　the　qualitative　and　quantitative　detection　of　PFOA,　with　a　quantitative　detection　limit　of　15.89　ppb.　The　results　of　this　paper　provide　a　new,　simple,　and　quick　method　for　the　detection　of　PFOA　in　the　environment.