By　using　the　biofilm　annular　reactor(BAR),　the　characteristics　of　microbial　growth　and　microbial　corrosion,　and　control　measures　of　shock　disinfection　of　a　new　stainless　steel　composite　pipeline　in　the　water　supply　system　of　municipal　and　construction　area　were　studied.　The　microbial　growth　on　the　stainless　steel　composite　pipeline　wall,　corrosion　rate　of　the　pipeline　caused　by　microorganism,　and　inactivation　efficiency　of　chlorine　disinfection　on　biofilm　were　also　investigated.　The　results　show　that　in　the　water　supply　pipe　network　system　of　municipal　and　construction　area　with　residual　chlorine,　biofilm　proliferation　of　stainless　steel　composite　pipeline　is　obvious　after　80　d　of　operation.　During　100-110　d,　the　biomass　reaches　the　peak,　and　both　the　turbidity　and　microbial　index　exceed　the　standard　values.　The　biofilm　of　the　wall　has　a　diversity　of　microorganisms　in　it,　which　contains　a　variety　of　pathogens,　chlorine　resistant　pathogens　and　bacteria　that　can　cause　metal　corrosion,　posing　a　potential　threat　to　the　biosafety　and　chemical　safety　of　drinking　water.　With　microorganisms　in　water,　the　corrosion　current　density　of　the　stainless　steel　composite　pipeline　increases,　the　corrosion　potential　decreases　and　the　corrosion　rate　increases　obviously.　With　high　mass　concentration　of　chlorine　and　long　sterilization　time,　the　inactivation　effect　of　biofilm　microbes　is　better.　When　the　chlorine　mass　concentration　is　5　mg/L,　iron　bacteria,　heterotroph　and　other　bacteria　can　be　completely　inactivated　when　sterilized　for　60　min.　After　the　shock　of　chlorine　disinfection,　the　biofilm　on　the　wall　peels　off,　and　biofilm　morphology　is　damaged.　The　longer　the　disinfection　time　is,　the　greater　the　degree　of　biofilm　damage　is,　which　can　effectively　control　the　corrosion　of　stainless　steel　composite　pipeline　caused　by　biofilm　and　assure　water　safety.　©　2018,　Central　South　University　Press.　All　right　reserved.