Sensor　placement　for　disaster　prevention　for　important　users　in　urban　water　distribution　networks　is　essential　for　post-earthquake　monitoring　and　repair.　Herein,　we　proposed　a　sensor　placement　approach　for　disaster　prevention　monitoring　for　important　users,　to　(a)　improve　the　fault　diagnosis　ability　of　the　water　distribution　network　and　to　(b)　guarantee　the　function　of　emergency　services　for　key　nodes　after　an　earthquake.　First,　an　evaluation　system　of　node　users＇　disaster　prevention　impact　factors　was　presented　to　evaluate　the　node　influence　degree　from　three　aspects:　post-earthquake　leakage,　emergency　support　and　topology　structure;　and　the　weight　values　of　node　users＇　disaster　prevention　impact　factors　were　obtained.　Second,　a　post-earthquake　hydraulic　analysis　model　based　on　the　pressure-driven　demand　was　used　to　calculate　the　water　shortage　ratio　of　nodes.　Third,　using　the　three-way　clustering　integration　method,　the　results　of　four　clustering　techniques　were　integrated　to　divide　the　monitoring　domain　in　the　water　distribution　network　based　on　sensitivity　analysis.　Finally,　on　basis　of　the　sensitivity　matrix,　the　division　of　the　monitoring　area　and　the　impact　factors　of　node　users＇　disaster　prevention　were　combined　to　place　sensors　for　post-earthquake　disaster　prevention　in　the　water　distribution　network.　Detailed　computational　experiments　for　a　real　urban　water　network　in　China　were　performed　and　compared　with　the　results　of　other　traditional　techniques　to　evaluate　the　performance　of　the　proposed　approach.　The　results　show　that　the　approach　is　better　than　traditional　methods.　It　not　only　considers　the　actual　hydraulic　information　of　the　water　distribution　network,　but　also　the　important　user　nodes　after　an　earthquake,　and　is　of　great　significance　for　emergency　command　and　rescue　and　disaster　relief　after　an　earthquake　in　the　city.