For the Fischer-Tropsch synthesis (FTS), this paper presents a numerical investigation in a 3D fluidized bed reactor. The effect of the operation parameters such as bed temperature, superficial gas velocities, particle size and bed heights is discussed. A 3D-CFD model coupled with FTS chemical kinetics was set up. The computational results are compared with experimental data in terms of the components production rates, etc. The analysis shows that the bed heights, the bed temperature, the superficial gas velocities and particle sizes affect the C5+ selectivity and the reaction rates. Product yields are dependent on the operating conditions especially the temperature. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.