The　optimization　between　heat　transfer　enhancement　and　flow　resistance　reduction　of　solar　salt　in　a　noncircular　twisted　tube　heat　exchanger　(NCTTHX)　was　studied.　Firstly,　the　effects　of　axis　ratio　(β),　inlet　velocity　(uin,solarsalt)　and　pitch　(Pt)　on　heat　transfer　and　flow　resistance　of　the　solar　salt　were　numerically　investigated.　Secondly,　the　mathematical　model　of　the　entropy　balance　for　heat　transfer　process　of　the　solar　salt　was　established,　where　the　modified　heat　transfer　entropy　generation　number　(HTEGN,　χ)　is　proposed.　Moreover,　the　modified　ZS-RSM　methodology　was　utilized　for　the　regression　of　Nusselt　number　(Nuoval),　heat　transfer　effectiveness　(Ε)　and　the　HTEGN　(χ).　Finally,　the　integration　of　the　NSGA-II　algorithm　and　modified　ZS-RSM　methodology　was　utilized　for　the　optimization　of　heat　transfer　enhancement　and　flow　resistance　reduction　for　solar　salt　in　the　NCTTHX.　The　results　show　that:　the　torsion　force　is　the　main　reason　that　can　improve　the　heat　transfer　performance,　where　ether　the　increase　of　β　and　uin,solarsalt　or　the　decrease　of　Pt　can　strengthen　the　effect　of　the　torsion　force.　There　is　a　coincidence　opposite　variation　trend　between　χ　and　Ε　at　constant　Re.　χ　can　effectively　describe　the　effect　of　changes　in　inlet　temperature　ratio　tao　on　heat　transfer　performance,　whereas　Ε　cannot.　The　prediction　by　the　modified　ZS-RSM　methodology　is　well　aligned　with　the　numerical　results.　When　the　minimum　χ　is　added　as　the　objective　function,　the　flow　resistance　and　heat　transfer　entropy　generation　number　decreases　by　6　%　and　0.6　%,　respectively;　however,　the　energy　efficiency　ratio　increases　by　6.2　%.　©　2025　Elsevier　Masson　SAS