Abstract: Pressurized fluidized bed coal catalytic hydrogasification technology demonstrates broad application prospects in the coal-to-natural gas field due to its high carbon conversion rate and methane yield. The fluidization number, as a key parameter affecting the performance of fluidized bed gasification, plays a significant role in regulating particle motion, mixing, and gas-solid mass and heat transfer processes within the bed, thereby influencing the temperature distribution, carbon conversion rate, and methane yield in the gasifier. However, systematic research on the fluidization number remains scarce, and a deeper understanding of its mechanism in the flow-transfer-reaction process of gasification is crucial for optimizing process parameters and reactor design. This study, based on computational fluid dynamics （CFD） simulation and employing the multiphase particle-in-cell （MP-PIC） model, investigates the effects of four fluidization numbers （2.0, 3.5, 5.0 and 8.0） on the coal catalytic hydrogasification performance. The results reveal that smaller bubble sizes generated under lower fluidization numbers effectively enhance carbon-hydrogen mass transfer efficiency, intensify the hydrogasification reaction process, and elevate the hot spot temperature in the bed. The peak hot spot temperature under the 2.0 fluidization number condition reaches 1555 K, exceeding the melting temperature of coal ash. An increase in the fluidization number promotes particle diffusion and movement within the bed, leading to a more dispersed and reduced hot spot temperature, with the maximum temperatures under the other three fluidization number conditions below 1300 K. Considering both reaction intensification and hot spot control, a fluidization number of 3.5 is identified as a recommended choice. Furthermore, this study tracks representative particles of different sizes, analyzing their motion trajectories, temperature evolution, and reactivity. It is found that particles with an initial diameter of 196 μm exhibit the best hydrogasification reaction characteristics under the synergistic effects of the high-temperature zone and the small-bubble-enhanced mass transfer region. Particles that are either too large or too small tend to accumulate at the bottom of the bed or become entrained into the dilute phase region, negatively impacting their reactivity. The corresponding results can provide theoretical guidance for the design and optimization of fluidized bed coal gasifiers.