Node　localization　technology,　as　an　important　technology　of　wireless　sensor　networks　communication,　whether　it　can　accurately　locate　is　the　most　important　prerequisite　to　support　site　of　the　monitoring　information.　Due　to　the　development　of　localization　technology　is　affected　by　environment　factor,　localization　precision　and　energy　consumption,　so　how　to　reduce　error　and　improve　positioning　accuracy　of　node　is　the　focus　of　the　current　research.　DV-hop　(Distance　Vector-hop)　is　put　forward　to　solve　the　problem　effectively,　which　can　effectively　use　beacon　nodes　position　to　estimate　unknown　nodes　position　and　improve　nodes　abilities　of　positing.　For　this,　the　paper　proposes　the　IMDV-hop　algorithm.　Considering　average　distance　of　the　whole　network　is　replaced　by　average　distance　of　beacon　nodes,　which　results　in　decline　in　the　localization　accuracy,　so　it　gives　new　average　hop　distance　Formula　in　order　to　effectively　reduce　error　between　whole　network　average　hop　distance　and　real　distance　values.　Then,　average　distance　of　the　whole　network　is　modified　by　introducing　proportional　parameter　to　make　it　approach　the　true　distance　for　achieving　the　improvement　of　the　positioning　accuracy.　The　results　show　that　the　IWDV-hop　(Improved　Weighted　Distance　Vector-hop)　algorithm　to　improve　positioning　accuracy　of　nodes　and　reduce　positioning　error　is　effective.