A new type of resistance internal with radial expansion was developed to overcome the major problems in large bubbling bed reactor, such as enhanced re-mixing, uneven distribution of  flow field and low mass transfer efficiency, which could affect the stable and efficient operation of the reactor and the safety of working conditions. The effect of resistance internal on bubble aggregation and fragmentation behavior was explored in cold model test platform, and the flow field flow characteristics of different combinations of resistance internals in a large reactor were investigated, and the flow field enhancement effect of resistance internal combinations in the industrial reactor amplification process was explored. The results show that the turbulent vortex scale is reduced and the bubble fragmentation probability is increased after the resistance internal is set in the cold model test device of bubble column reactor, and the average diameter of the bubble population decreases from 13.48-24.38 mm to 9.40-20.38 mm after different bubble populations pass through the resistance internal, and the surface area is increased by 8.5%-71.9%.The installation of the resistance internal can improve the uniformity of local gas holdup and liquid velocity distribution in the reactor, and the axial influence range of the flow field can be expanded by increasing the number of resistance internal layers. Increasing the diameter of the resistance internal is beneficial to reduce the difference of the local liquid velocity in each height plane and improve the uniformity of the radial distribution of the local gas holdup. The difference of the central liquid velocity in different height planes is reduced from 0.6 mm/s to 0.3 mm/s, and the variance of the local gas holdup in the same height plane can be reduced to 15% of that without the resistance internal. The radial range of fluid flow around the reactor is expanded during the process of reactor amplification, and the uniformity of local gas holdup and liquid velocity distribution is further reduced. The variance of local gas holdup in the same height plane can be reduced to 7% of that without the resistance internal, and the difference of local liquid velocity is reduced from 1.3-2.7 mm/s to 1.0-1.1 mm/s after setting the resistance internal combination. When a 1/4 times tower diameter distributor is set and the resistance internal combination is set in the way of installation interval :distributor diameter=7∶1, the flow field strengthening effect is better.