To optimize the gasification performance of Shell gasifier, the balance model of Shell entrained-flow pulverized coal gasification process was established by using Aspen Plus software. Four modules were mainly investigated, including pyrolysis, combustion, gasification, cold gas chilling and sensible heat recovery of waste heat boiler. The impacts of oxygen/coal ratio and steam/coal ratio on the gasification performance of Shell gasifier were investigated. The results show that with the increase of oxygen/coal ratio, the concentration of H2 and CH4 decreases, the concentration of CO2 increases slowly and then increases rapidly. The concentration of CO and cold gas efficiency increase first and then decrease. With the increase of steam/coal ratio, the concentration of H2 and CO2 increases, the concentration of CO and CH4 decreases, the efficiency of cold gas increases rapidly and then decreases slowly. The optimal ratio of oxygen/coal and steam/coal of Shenfu coal is 0.86 and 0.05 respectively.