Abstract: Thephaselockedloop(PLL)swingscanningcontrolmethodisextensivelyappliedforaerospaceopticsscanningremotesensor,whichcanberealizedwithsimpleandreliablecontrolcircuit.However,thecontrolsystemmodeliscomplicatedforphasedetectornon-linearityandswitcheffectofspringslices,anditisdifficulttoanalysisanddesignforthiscontrolsystem.Thevariousnonlinearcharactersin PLL swingscanningcontrolsystemwereanalyzed,andalinearizedmodelwasobtainedbyapplyingsmall-signalanalyticmethod,whichwasconvenientforanalysisanddesign.Basedontheproposedmodel,thecontrollerdesignrulewasalsodiscussed，andanexperimentwascarriedouttoconfirmtheanalysisconclusion.

Key words: Swingscanning, Controlsystem, Nonlinearsystem, Phaselockedloop, Aerospaceopticsremotesensing