The　POI　data　and　Place2vec　model　within　the　third　ring　of　Fuzhou　City　were　used　to　identify　the　functional　zones　in　the　city,　on　the　basis　of　which　we　were　able　to　analyze　the　characteristics　of　the　spatial　differentiation　of　the　thermal　field　levels　in　each　functional　zone.　We　subsequently　constructed　the　functional　zone　warming　sensitivity　index　using　a　boosting　regression　tree　algorithm　to　quantitatively　measure　the　sensitivity　difference　of　different　functional　zones　in　the　process　of　surface　warming　and　then　explored　the　spatial　differentiation　mechanism　of　the　urban　thermal　environment　on　a　regional　scale.　The　results　showed　the　following.　First,　the　identification　framework　of　urban　functional　zones　was　constructed　based　on　POI　data　and　the　Place2vec　model;　and　the　identification　of　the　five　types　of　functional　zones—the　living　service　and　residential　zone,　public　management　and　service　zone,　commercial　zone,　industrial　zone,　green　space　and　square　zone—was　highly　accuratecy.　Second,　the　internal　thermal　field　grades　of　the　green　space　and　square　zone　are　mainly　low-temperature　and　sub-low-temperature,　while　the　rest　of　the　four　types　of　internal　surface　heat　field　grades　of　functional　zones　are　dominated　by　medium-temperature,　sub-high-temperature,　high-temperature,　and　very-high-temperature　zones.　Additionally,　the　distribution　of　sub-low-temperature,　low-temperature,　and　very-low-temperature　zones　is　not　significant.　Except　for　the　green　space　and　square　zone,　all　four　types　of　functional　zones　exhibit　high-temperature　phenomena,　of　which　the　extremely　high-temperature　zone　accounts　for　the　most　in　the　industrial　zone　(as　high　as　20.68%)　and　the　least　in　the　green　space　and　square　zone(1.90%).　Third,　the　overall　sensitivity　to　temperature　increase　of　each　type　of　functional　zone,　in　descending　order,　is　as　follows:　industrial　zone,　living　service　and　residential　zone,　commercial　zone,　public　management　and　service　zone,　green　space　and　square　zone.　The　sensitivity　to　temperature　increase　of　each　functional　zone　in　different　warming　stages　differs　significantly　under　the　high-temperature　gradient.　The　sensitivity　to　temperature　increase　of　the　ground　cover　of　different　functional　zones　has　the　distinctive　characteristics　of　the　functional　zones.　Specifically,　the　higher　the　degree　of　development　of　the　zone,　the　higher　the　sensitivity　to　temperature　increase　of　the　built　land.　The　higher　the　degree　of　regional　construction　development,　the　greater　the　difference　between　the　sensitivity　of　construction　land　and　the　sensitivity　of　vegetation　and　water,　and　the　sensitivity　of　construction　land　is　always　higher　than　the　sensitivity　of　vegetation　and　water　in　each　functional　zone.　The　results　of　this　study　will　help　overcome　the　limitations　of　existing　urban　thermal　environmental　research　and　provide　a　scientific　decision-making　basis　for　promoting　the　rational　layout　of　urban　functional　areas,　alleviating　the　urban　heat　island　effect,　preventing　the　risk　of　high　temperatures　under　extreme　weather　conditions,　and　realizing　sustainable　urbanization.　©　2024　Editorial　Committee　of　Tropical　Geography.　All　rights　reserved.