The　algae　pollution　of　reservoir　water　is　serious　increasingly,　the　traditional　process　of　sedimentation　solid-liquid　separation　hardly　meets　the　requirement　of　clearwater.　GAC-sand-double-filtration　flofilter　was　built　to　treat　the　high　algae　reservoir　water　derived　from　yellow　river,　and　the　running　and　operating　characteristics　of　this　flofilter　were　investigated.　The　experiment　results　showed　that,　the　effect　of　running　was　excellent　when　polyaluminum　ferric　chloride(PAFC)　dosage　was　4.0　mg·L-1　(Al3+),　air　pressure　0.4　MPa,　and　reflux　ratio　8%.　Biomass　of　GAC　and　sand　filter　layer　mainly　existed　in　the　carbon　layer,　which　accounted　for　97.4%　(the　highest　value　was　50.2　nmol　P·g-1),　and　its　biomass　was　16.7　times　of　sand　layer　(3.0　nmol　P·g-1),　so　the　removal　of　pollutants　occured　mainly　in　the　carbon　layer.　During　the　test,　removal　efficiency　of　particulate　matter,　blue-green　algae,　turbidity,　CODMn,　NPOC,　UV254,　ammonia　nitrogen　reached　96.48%,　92.40%,　92.56%,　57.41%,　51.60%,　52.50%,　75.67%　respectively.　Odor　reduced　from　4　to　0.Contents　of　geosmin　and　methylisoborneol　were　both　less　than　the　detection　limit.　Removal　efficiency　of　chloroform,　chlorodibromomethane　reached　60%　and　55.1%.　The　results　showed　that,　flofilter　process　had　a　great　removal　on　conventional　index,　algae,　odor　substances　and　disinfection　byproducts　precursors.　©　All　Rights　Reserved.