In　order　to　study　the　distribution　law　of　temperature　in　deep　water　CML　dual-gradient　drilling　wellbore,　the　coupling　relationship　between　wellbore　temperature,　pressure,　drilling　fluid　density　and　rheological　properties　was　comprehensively　considered,　and　the　transient　heat　transfer　model　of　deep　water　CML　dual-gradient　drilling　wellbore　was　established　in　combination　with　the　characteristics　of　deep-water　CML　dual-gradient　drilling　process　and　the　law　of　energy　conservation.　Based　on　an　example　well,　the　effects　of　cycle　time　and　drilling　fluid　physical　parameters　on　annulus　temperature　were　analyzed　and　compared　with　conventional　drilling.　The　results　show　that　the　annulus　temperature　in　the　lower　part　of　the　wellbore　decreases　and　the　annulus　temperature　in　the　upper　part　increases　with　the　increase　of　the　cycle　time　and　the　density,　specific　heat　and　consistency　coefficient　of　the　drilling　fluid.　With　the　increase　of　thermal　conductivity　of　drilling　fluid,　the　annulus　temperature　in　the　lower　part　of　wellbore　increases　gradually,　while　the　annulus　temperature　in　the　upper　part　decreases　gradually.　Compared　with　the　wellbore　temperature　of　conventional　drilling,　the　overall　wellbore　temperature　of　CML　drilling　is　about　3　°C　lowers　on　average,　and　the　temperature　difference　near　the　mud　line　can　reach　about　8　°C.　©　2021,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Switzerland　AG.