TheS2flowpathdesignmethodofthetransoniccompressorisusedtodesigntheonestagefaninordertoreplacetheoriginaldesignedbladecascadewhichhastwo-stagetransonicfanrotors.Inthemodificationdesign,thecamberlineisparameterizedbyaquarticpolynomialcurveandthethicknessdistributionofthebladeprofileiscontrolledbythedouble-thricepolynomial.Therefore,theinletflowhasbeenpre-compressedandthelocationandintensityoftheshockwaveatsupersonicareahavebeencontrolledinordertoletthenewbladeprofileshavebetteraerodynamicperformance.Thecomputationalresultsshowthatthenewsinglestagefanrotorincreasestheefficiencybytwopercentatthedesignconditionandthetotalpressureratioisslightlyhigherthanthatoftheoriginaldesign.Atthesametime,italsomeetsthemassflowrateandthegeometricalsizerequirementsforthemodificationdesign.