Abstract: Atpresent，solvingthethreedimensionalPoissonequationofcomplexelectricfieldintheelectricthrusterstillhasthedisadvantagesofslownessandpoorparallelism.
Asuccessiveoverrelaxationparallel（PSOR）iterativealgorithmwasproposedtosolvethethreedimensionalPoissonequationbasedontheideaofdomaindecomposition.Thesolutionregionwasdividedintoseveralsubdomains.AndanumberofexplicitschemeswereconstructedbyusingtheSORmethod.Thenaccordingtothedifferentschemes，thesolvingequationsfordifferentiterativestepsweregivenforparallelcomputation.Thenumericalsimulationresultsshowthatthecalculationtimeisreducedbyatleasthalf.AndthePSORmethodhasmadegreatprogressinthecomputationspeedcomparedwiththetraditionaliterativescheme.

Key words: electricthruster, Poissonequation, successiveoverrelaxationiteration, parallelalgorithm