To　study　decomposition　of　formaldehyde　with　high-frequency　dielectric　barrier　discharge,　the　influence　of　parameters　of　DBD　reactor　structure　on　decomposition　of　formaldehyde　is　investigated,　and　the　removal　mechanism　of　formaldehyde　by　the　low　temperature　plasma　from　DBD　is　analyzed.　The　experimental　results　show　that　the　central　electrode　diameter　and　the　internal　diameter　of　dielectric　tube　significantly　influence　the　decomposition　efficiency　of　formaldehyde.　Both　diameters　ought　to　be　optimized　to　maximize　the　decomposition　efficiency.　As　a　discharge　electrode　of　the　reactor,　tungsten　filament　is　better　than　brass　wire　and　stainless　steel　wire.　Adopting　99　ceramic　tubes　with　higher　relative　dielectric　constant　as　dielectric　barrier,　the　decomposition　efficiency　of　formaldehyde　is　increased　from　41%　to　76%.　The　reaction　length　has　an　optimum　value　when　power　is　fixed.