Rural　settlements　are　developing　in　the　direction　of　functional　diversification,　driven　by　rapid　urbanization,　but　also　leading　to　a　decline　in　their　vitality　as　a　result　of　the　rapid　concentration　of　rural　population　in　cities.　Therefore,　this　study　proposed　a　theoretical　framework　to　refine　the　optimization　approach　for　rural　settlements　from　the　perspective　of　＂production-living-ecological＂　functions　(PLEF)　and　vitality.　Taking　a　town　in　the　farming-pastoral　ecotone　in　northern　China　as　a　case,　we　evaluated　the　level　of　the　PLEF　of　rural　settlements.　After　exploring　the　functional　requirements　of　villagers,　we　revealed　the　vitality　of　rural　settlements　based　on　social　network　analysis.　The　Tapio　decoupling　model　was　used　to　identify　the　optimization　type　of　rural　settlements　considering　the　PLEF　and　vitality.　The　results　showed　that　the　PLEF　of　rural　settlements　was　higher　in　areas　with　flat　terrain,　convenient　transportation,　and　rich　economies.　Rural　settlements　closer　to　the　central　town　were　stronger　in　vitality.　The　PLEF　of　rural　settlements　was　generally　correlated　with　vitality,　which　means　that　rural　settlements　with　a　higher　level　of　PLEF　also　had　a　stronger　vitality.　Rural　settlements　were　classified　into　five　types:　suburban　integration,　characteristics　protection,　agglomeration　and　upgrading,　general　survival,　relocation,　and　merger,　according　to　the　characteristics　of　a　combination　of　PLEF　and　vitality.　This　study　contributes　to　a　deeper　comprehension　of　the　functional　and　structural　characteristics　of　rural　settlements　and　will　be　beneficial　in　guiding　rural　spatial　reconstruction.