Deep　borehole　heat　exchanger　of　deep　ground-source　heat　pump　is　investigated　by　numerical　simulation　and　experimental　validation.　The　deep　borehole　heat　exchanger　heat　transfer　model　concerning　the　axial　temperature　gradient　is　established　by　Matlab,　the　simulated　calculations　and　the　accuracy　of　model　are　proved　by　demonstration　project　test　data.　Through　a　study　on　the　stability　of　heat　transfer　performance　of　deep　borehole　heat　exchanger,　it　is　found　that　the　performance　of　deep　borehole　heat　exchanger　is　basically　stable.　Soil　temperature　recovery　is　fine　at　different　run-stop　ratios.　The　research　shows　that　the　deep　borehole　heat　exchanger　has　better　heat　exchange　performance　and　operation　stability,　provides　a　new　idea　for　the　development　and　application　of　deep　geothermal　energy.　©　2020,　Solar　Energy　Periodical　Office　Co.,　Ltd.　All　right　reserved.