Effect　of　silver　ions,　silver　ions-UV　combined　disinfection　on　microbes　was　investigated　by　using　a　domestic　hot　water　biofilm　annular　reactor.　The　results　showed　that　silver　ion　dosage　had　a　significant　effect　on　the　inactivation　of　microbes.　The　disinfection　by　0.05mg/L　silver　ion　achieved　excellent　microbial　inactivation　effect　in　60min.　Low　dosage　of　silver　ion　had　the　same　disinfection　efficiency　when　the　sterilization　time　was　increased.　The　inactivation　rate　of　Escherichia　Coli　by　silver　ion　was　low.　Hence,　adequate　concentration　and　disinfection　(CT)　value　need　to　be　ensured.　The　concentration　of　silver　ions　attenuated　slowly,　resulting　in　high-efficiency　inactivation　ratio　above　48h.　Moreover,　the　significant　damage　to　the　biofilm　structure　was　caused　by　all　three　disinfection　method　in　a　very　short　period.　Among　them,　UV　disinfection　had　the　least　effect　on　biofilm　structure,　while　silver　ion-UV　combined　disinfection　had　the　greatest　effect　on　biofilm　structure.　It　was　demonstrated　by　16s　rDNA　approaches　that　the　sterilization　ratio　of　silver　ions　to　pathogenic　microorganism　was　relatively　low　and　the　sterilization　ratio　of　UV　and　silver　ion-UV　combined　disinfection　was　relatively　high　on　the　contrary.　Therefore,　silver　ion-UV　combined　disinfection　possessing　the　advantages　of　both　UV　disinfection　and　silver　ion　disinfection,　comprehensively　improves　the　domestic　hot　water　biofilm　microbial　disinfection　efficiency,　which　is　a　valuable　technology　for　domestic　hot　water　disinfection.　©　2017,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.