Rapid　acquisition　of　environmental　parameters　of　emergency　sites　is　crucial　for　emergency　response.　However,　in　areas　where　public　ground　networks　do　not　provide　sufficient　coverage　or　are　destroyed　by　disasters,　the　rapid　backhaul　of　monitoring　data　from　emergency　sites　is　difficult.　Due　to　the　urgent　demand　for　data　collection　in　such　areas,　we　propose　an　unmanned　aerial　vehicle　(UAV)-aided　emergency　environmental　monitoring　system　using　a　LoRa　mesh　networking　approach,　which　can　quickly　build　a　large　range　of　wireless　communication　networks　suitable　for　small　data　transmission.　First,　we　designed　a　LoRa-based　mesh　network　protocol　by　using　a　custom　slotted　ALOHA　medium　access　mechanism.　Second,　we　designed　and　implemented　a　custom　software　and　hardware　platform　of　the　monitoring　system.　The　system　adopts　a　communication　mode,　including　multiple　sensor　nodes　(SNs),　multiple　relay　nodes　(RNs),　a　gateway　(GW),　and　a　network　server.　Finally,　we　demonstrated　the　performance　of　the　protocol　and　the　system　by　in-lab　and　outdoor　tests.　The　results　show　that　when　data　rate　is　0.293　kb/s,　the　line-of-sight　1-hop　transmission　distance　is　more　than　10　km,　and　the　1-hop　transmission　delay　is　less　than　6　s;　the　end-to-end　delay　has　an　upper　bound,　which　can　meet　the　real-time　requirement　of　emergency　response;　the　least　upper　bound　of　throughput　per　slot　of　our　mesh　protocol　is　much　higher　than　that　of　LoRaWAN.　Evaluation　results　also　demonstrate　the　network　robustness　to　environmental　changes.