Molten　salt　is　one　of　the　most　promising　heat　transfer　and　thermal　energy　storage　medium　for　the　third-generation　solar　thermal　power　generation,　and　the　spiral-wound　tube　heat　exchanger　can　improve　the　heat　transfer　performance　of　molten　salt.　In　this　paper,　the　flow　and　heat　transfer　characteristics　of　molten　salt　nanofluids　in　spiral-wound　tubes　are　experimentally　and　numerically　studied.　Molten　salt　nanofluids　and　synthetic　oil　as　the　heat　transfer　fluids,　the　heat　transfer　performance　of　them　in　the　spiral-wound　tube　heat　exchanger　were　studied.　The　Wilson　separation　method　was　used　to　process　the　experimental　data,　and　the　heat　transfer　correlation　of　molten　salt　nanofluids　is　obtained　through　experiments.　The　heat　transfer　correlation　can　be　in　good　agreement　with　the　experimental　data,　the　heat　transfer　correlation　on　the　molten　salt　nanofluids　side　is　Nu=0.3897Re0.4370Pr1/3,　Re　=　4296–8348,　Pr　=　13–23,　and　the　maximum　error　is　17.9%.　A　three-dimensional　model　of　the　spiral-wound　tube　heat　exchanger　is　used　to　explore　the　distribution　of　the　pressure,　temperature　and　velocity　fields　of　the　molten　salt　nanofluids.　The　friction　factor　correlation　on　the　molten　salt　nanofluids　side　is　f=4.6729Re−0.4855,　Re　=　3536–17684,　Pr　=　13–23　and　the　maximum　error　is　12.65%.　The　heat　transfer　correlation　and　resistance　correlation　of　molten　salt　nanofluids　obtained　in　this　paper　can　contribute　to　the　design　of　heat　exchanger　for　the　third-generation　solar　thermal　power.　©　2023