Taking　the　geothermal　heat　exchanger　as　an　object,　the　heat　exchanger　thermal　resistance　of　each　link　was　simulated　by　the　Fluent　software.　A　double　U-tube　geothermal　heat　exchanger　of　two-dimension　model　was　established,　and　the　heat　transfer　process　of　the　drilling　was　simulated.　The　theoretical　results　and　simulation　results　were　compared　to　verify　the　accuracy　of　the　simulation　model,　and　the　effect　of　the　accuracy　with　the　changes　of　tube　pitch,　PE　tube　outer　diameter　and　borehole　radius　for　thermal　resistance　of　PE　pipe　and　borehole　were　discussed.　The　results　show　that　the　simulation　and　theoretical　values　of　the　thermal　resistance　of　PE　pipe　and　borehole　outside　are　very　similar,　while　the　accuracy　of　the　calculated　by　the　theory　of　borehole　thermal　resistance　is　poor.　There　is　a　large　deviation　between　the　calculated　value　and　the　analog　value.　Tube　pitch　and　drilling　radius　have　no　effect　on　the　relative　error　of　the　theoretical　value　and　analog　values.　The　relative　error　of　the　borehole　thermal　resistance　between　the　theoretical　value　and　the　analog　value　grows　while　the　PE　pipe　diameter　increases.　It　can　provide　a　good　reference　for　the　design　of　ground　source　heat　pump.　©　2017,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.