Abstract: Theessentialrelationshipbetweensecondaryelectronsemissionand chargingstatesofdielectricwasinvestigatedbasedonchargingbalancemodewithnumericalsimulat ion.BothMonteCarloandfinitedifferencetimedomainalgorithmswereadoptedfornumericalsimulat ion， consideringelasticandinelasticessentialbetweenincidentelectronsandmaterialatomsduringscatte ringprocessandcalculatingdiffusion， driftandtrapeffectsofinternalcharges.Underdifferentchargingbalancemodes， thesecondaryelectronemissionandchargingstatesofdielectricontransientchange， internaldistributionsandsaturationvalueswereanalyzedandsimulated.Theresultsshowthatchargi ngbalancemodescanbedividedintothesecondaryelectron（SE）mode，theleakageelectron（LE） modeandthecombined（CO）mode.TheSEmodecorrespondstothesurfacechargingstate，whiletheLE modecorrespondstothedeepchargingstate.WhenthechargingbalancemodechangestowardsSEmod efromLEmode，boththesecondaryelectronyieldandthenegativesurfacepotentialincreases，while variationtrendsofthetotalchargingquantityandchargingtimeconstantpresenttobeopposite asaresultofbalancemodechange.

Key words: secondaryelectronemission, balancemode, chargingeffect, electronirradiation, numericalsimulation electronirradiation, numericalsimulation