In　this　study,　a　modified　refrigeration　cycle　(MRC)　using　refrigerant　mixture　R170/R290　was　proposed　for　applications　in　low-temperature　freezers.　Different　from　traditional　auto-cascade　cycle　(ARC),　additional　recuperator　and　expansion　valve　are　set　between　condenser　and　separator　to　realize　phase　separation　at　an　intermediate　pressure.　The　MRC　can　significantly　improve　volumetric　refrigeration　capacity　(qev)　and　the　coefficient　of　performance　(COP)　especially　in　low　evaporating　temperature　condition.　As　evaporating　temperature　is　set　at　−60°C,　using　MRC　system　can　acquire　18%　and　35%　COP　and　qev　improvements,　and　the　compression　ratio　in　MRC　reduced　23%　in　comparison　to　ARC.　In　general,　decreasing　both　separating　temperature　and　quality　of　condenser　outlet　will　benefit　the　performance　of　MRC.　Besides,　there　exist　an　appropriate　mixture　quality　at　evaporator　outlet　to　obtain　the　best　COP　and　qev　under　the　given　condition.　©　2018　Elsevier　Ltd　and　IIR