Forthemulti-frequencyacousticanalysis,aseriesexpansionmethodhasbeenintroducedtoreducethecomputationtimeofthefrequency-independentparts,buttheRungephenomenonwillarisewhenthismethodisemployedinhighfrequencyband.Therefore,thismethodisimprovedbyanalyzingtheapplicationconditionandproposingtheselectionprincipleoftheseriestruncationnumber.Theargumentintervalcanbeadjustedwiththewavenumberfactor.Therefore,theproblemofunstablenumerationandpoorprecisioncanbesolved,andtheapplicationscopeofthismethodisexpanded.Thenumericalexampleofacousticradiationshowsthattheimprovedmethodiscorrectforacousticanalysisinwiderfrequencybandwithlessseriestruncationnumberandcomputationamount.
