Abstract: Traditionalmultipactorpredictionmethodbasedonplaneapproximationisfastbutinaccurate,whichcannotmeettheelectricalperformancedesignrequirementswhendevicesbecomemoreandmorecomplex.Thefinitedifferencetimedomainalgorithmisoneofthemostpopularmethodsinthecomputationalelectromagnetics.TheparticletracingalgorithmisanumericalmethodbasedontheNewton'sforcelaw. Thetwoalgorithmscanbeselfconsistentlycombinedbythediscretemeshinbothtimeandspacedomains,whichcanbeusedtopredictthemultipactorbreakdownthreshold.Inaddition,theconformalandparallelizingtechnologieswerewellstudied.Multipactorbreakdownofclassicmicrowavedevicewasanalyzedbythedevelopedalgorithm.Theerroris0.3dBcomparedwiththeexperimentsandthemaximumparallelefficiencyis83%,whichdemonstratetheaccuracyandefficiencyofthealgorithm.

Key words: finitedifferencetimedomain, particletracing, multipactor, conformal, parallelization