Abstract: In order to obtain the reaction characteristics, CO methanation process is numerically investigated in fluidized bed catalytic reactor over Ni/Al2O3 catalyst. The catalysts flow behavior is analyzed, which has significant effect on the activity of catalysts. The influences of operation parameter on CO conversion and CH4 yield are evaluated. The inventory of catalysts and superficial gas velocity will not influence the output of methane but the reaction rates. Meanwhile, the performance of water-gas shift reaction on CH4 yield is taken consideration during reactions.