In　this　study,　a　numerical　simulation　method　based　on　Eulerian–Eulerian　model　and　population　balance　model　(PBM)　(i.e.,　computational　fluid　dynamics　(CFD)–PBM　coupling　model)　was　developed　to　investigate　the　gas–liquid　two-phase　performance　of　centrifugal　pump　under　bubble　inflow.　The　realizable　k–e　model　turbulence　model　was　implemented　in　ANSYS　FLUENT　solver.　The　air　and　water　were　employed　as　the　working　fluids,　which　was　consistent　with　the　experiment.　The　water　head　and　pressure　increment　obtained　by　the　experiment　were　used　to　validate　the　numerical　method.　The　results　show　that　the　CFD–PBM　coupling　model　is　superior　to　the　Eulerian–Eulerian　model,　particularly　in　the　＇surging＇　conditions.　Using　the　CFD–PBM　coupling　model,　the　influences　of　parameters,　such　as　inlet　gas　volume　fraction,　liquid　phase　flowrate,　and　rotational　speed,　on　the　head　and　efficiency　of　the　centrifugal　pump　were　investigated.　Under　the　design　condition,　when　the　inlet　gas　volume　fraction　increases　from　3%　to　5%,　the　bubbles　form　air　mass　and　stagnate　in　the　impeller　channel.　The　stagnated　air　mass　can　hardly　be　discharged　with　the　liquid　phase.　Thus,　the　pump　head　drops　suddenly,　i.e.,　the　surging　occurs.　The　two-phase　performance　of　centrifugal　pump　can　be　improved　under　the　surging　condition　by　increasing　the　liquid　flowrate　and　the　rotational　speed　to　a　certain　value.　The　results　contribute　to　an　alternative　simulation　method　to　investigate　the　characteristics　of　bubble　flow　in　pump　and　shed　new　lights　on　the　understanding　of　the　performance　of　centrifugal　pumps　under　two-phase　flow　conditions.　Copyright　©　2020　by　ASME.