In　this　study,　it　is　found　that　there　exist　several　low-pressure　regions　whose　pressure　is　lower　than　that　of　the　entrained　steam　inside　the　ejector　under　both　its　designed　and　non-designed　conditions.　Thus　a　novel　steam　ejector　with　auxiliary　entrainment　is　proposed　to　take　full　use　of　the　possible　low-pressure　regions　to　entrain　the　extra　low-grade　entrained　steam　for　energy　conservation　and　performance　improvement.　The　internal　flow　fields　in　the　steam　ejector　with　and　without　auxiliary　entrainment　have　been　obtained　numerically.　Analysis　and　research　are　mainly　focused　on　the　influences　of　the　mixing　chamber,　ejector　throat,　diffuser　auxiliary　and　combined　auxiliary　entrainment　on　the　mass　flow　rate,　the　entrainment　ratio,　the　internal　pressure　field　and　the　shock　wave　phenomena　of　a　given　ejector.　The　results　reveal　that　the　throat　and　diffuser　auxiliary　entrainment　can　increase　the　entrainment　ratio　of　the　steam　ejector　under　the　simulated　operation　conditions.　The　throat　auxiliary　entrainment　is　a　feasible　choice　for　ejectors　operating　under　the　designed　conditions　and　the　combined　auxiliary　entrainment　of　the　throat　and　the　diffuser　is　the　best　choice　for　ejectors　operating　under　non-designed　conditions.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.