The multiphase reaction flow in entrained flow gasifiers using de-oiled asphalt (DOA) as feedstock was studied by numerical simulation. The influences of mO2/mDOA, mH2O/mDOA and gasifier pressure on gasifier characteristics were discussed. The results show that with the increasing of mO2/mDOA, the gas temperature increases. The volume fraction of CO and H2 reaches maximum(0.837), when mO2/mDOA is 0.93. With the increasing of mH2O/mDOA, the gas temperature decreases, and the proportion of effective gases (CO+H2) reaches maximum when mH2O/mDOA is 0.48. The operation pressure has little effect on gasifier outlet gas composition and temperature.