In thisstudy,nonlinearvibrationandstabilityofa fluid-conveyingnanotube(FCNT),elasticallycoupled to asmartpiezoelectricpolymericbeam(PPB)isinvestigatedbasedonnonlocalelasticitytheory,Euler– Bernoulli beammodelandenergyapproach.InordertoobtainanactiveinstabilitycontrolofFCNT,the PPB islongitudinallypolarizedasanactuatorwhileintheabsenceofanimposedelectric field itisalso possible tobeusedasanalarmbiosensor.Simulatingtheabovesmartcouplednanobeamsystemalike the doublenanobeamsystems(whicharerelativelydevelopedbyotherauthors)leadstoobtain nonlinear differentialequationsofmotion.Thelinearnaturalanddampingfrequenciesareachievedby ignoring allthesystemnonlinearitieswhicharethenconsideredtoobtainnonlinearfrequenciesusing an iterativemethod.Theeffectsofgeometricnonlinearity,smallscaleparameter,coupledmedium constants, Knudsennumber,temperaturechange,aspectratioandexternalappliedvoltageoncritical flow velocityarestudiedindetails.ItisconcludedthatapplyinganelectricvoltageonPPBwillincrease the stabilityofFCNT.Itishopedthatthisresearchwillprovideanewapproachtosmartinstability control ofFCNTswhichisnoyetreported.