Aiming　at　biosafety　problem　in　the　domestic　hot　water　system　(DHWS),　the　inactivation　efficiency　of　biofilm　microorganisms　on　the　living　hot　water　pipeline　wall　by　the　disinfection　methods　of　silver　ion,　thermal　energy　and　silver　ion-thermal　energy　compound　impact　disinfection　technology　was　comparatively　studied.　The　results　show　that,　the　concentration　of　silver　ion　and　the　temperature　of　the　hot　water　have　a　significant　influence　on　inactivation　of　the　total　number　of　bacteria　and　Escherichia　coli　of　the　biofilm　on　the　DHWS　pipeline　wall.　The　effect　of　silver　ion-thermal　energy　compound　impact　disinfection　technology　is　better　than　that　of　single　silver　ion　disinfection　or　thermal　energy　thermal　energy　significantly.　The　effect　of　compound　impact　disinfection　technology　with　60　hot　water,　0.05　mg/L　silver　ions　and　60　min　of　disinfection　is　close　to　single　thermal　energy　disinfection　technology　of　70,　but　the　disinfected　biofilm　becomes　thin　and　shed,　and　biofilm　structure　is　damaged　significantly.　And　the　silver　ion-thermal　energy　compound　impact　disinfection　technology　can　significantly　improve　the　inactivation　effect　of　biofilm　microbes　on　the　wall　of　DHWS　pipeline　and　can　kill　the　pathogenic　microorganisms　efficiently,　which　is　a　valuable　technology　for　safety　disinfection　and　water　quality　protection　of　DHWS.　©　2019,　Editorial　Department　of　Transaction　of　Beijing　Institute　of　Technology.　All　right　reserved.