Carbon　nanotube　nanofluids　have　wide　application　prospects　due　to　their　unique　structure　and　excellent　properties.　In　this　study,　the　thermal　conductivity　properties　of　carbon　nanotube　nanofluids　and　SiO2/water　nanofluids　were　compared　and　analyzed　experimentally　using　different　preparation　methods.　The　physical　properties　of　nanofluids　were　tested　using　a　Malvern　Zetasizer　Nano　Instrument　and　a　Hot　Disk　Thermal　Constant　Analyzer.　Combined　with　field　synergy　theory　analysis　of　the　heat　transfer　performance　of　nanofluids,　results　show　that　the　thermal　conductivity　of　carbon　nanotube　nanofluids　is　higher　than　that　of　SiO2/water　nanofluids,　and　the　thermal　conductivity　of　nanofluid　rises　with　the　increase　of　mass　fraction　and　temperature.　Moreover,　the　synergistic　performance　of　carbon　nanotube　nanofluids　is　also　superior　to　that　of　SiO2/water　nanofluids.　When　the　mass　fraction　of　the　carbon　nanotube　nanofluids　is　10%　and　the　SiO2/water　nanofluids　is　8%,　their　field　synergy　numbers　and　heat　transfer　enhancement　factors　both　reach　maximum.　From　the　perspective　of　the　preparation　method,　the　thermal　conductivity　of　nanofluids　dispersed　by　high　shear　microfluidizer　is　higher　than　that　by　ultrasonic　dispersion.　This　result　provides　some　reference　for　the　selection　and　use　of　working　substance　in　a　microchannel　cooling　concentrated　photovoltaic　and　thermal　(CPV/T)　system.