A　kind　of　shell-and-tube　heat　exchangers　with　fold　helical　baffles　was　proposed　to　eliminate　the　triangular　leakage　zones　between　adjacent　baffles　and　shell.　The　effect　of　helical　angle　and　overlapped　degree　on　flow　and　heat　transfer　for　shell-and-tube　heat　exchanger　with　fold　helical　baffles　was　studied　based　on　investigation.　The　experimental　correlations　of　convection　heat　transfer　coefficient　and　resistance　coefficient　in　shell　side　were　obtained.　The　results　show　that　the　shell-side　total　pressure　drop,　shell-side　tube　bundle　pressure　drop,　shell-side　heat　transfer　coefficient　and　comprehensive　performance　all　increase　with　the　decrease　of　helical　angle　and　the　increase　of　overlapped　degree　under　same　shell-side　volume　flow　rate.　The　flow　and　heat　transfer　performance　of　shell-and-tube　heat　exchanger　with　helical　baffles　is　the　best　when　helical　angle　is　18°　and　overlapped　degree　is　50%.　The　helical　angle　and　overlapped　degree　as　correction　factor　are　added　into　experimental　correlations.　It　is　found　that　the　average　relative　error　between　experimental　values　and　experimental　correlation　of　Nusselt　number　is　1.13%,　the　average　relative　error　is　6.84%　between　experimental　values　and　experimental　correlation　of　resistance　coefficient,　which　illustrates　the　fitting　is　correct　and　reliable.　The　results　have　a　degree　of　theoretical　guidance　for　design　of　shell-and-tube　heat　exchangers　with　fold　helical　baffles.　©　All　Right　Reserved.