The application of solid particles in the next-generation concentrated solar power station could reduce the Levelized Cost of Energy further. As a key energy conversion device, existing particle solar receivers still have different shortcomings. The high-density countercurrent fluidized bed (CCFB) particle solar receiver may provide a promising technical solution because of its feasibility and its thermal transportation characteristics. However, the hydrodynamics of the CCFB particle solar receiver is very difficult to investigate through experimental methods. In this study, a computational particles fluid dynamics model is established to investigate the gas–solid flow characteristics in the CCFB particle solar receiver, which is validated by the experimental solid mass flow rate obtained from a cold mold CCFB particle solar receiver. The solid holdup distribution, axial particle velocity and characteristics of bubbles are obtained accordingly. The results show that the present model can capture the entire process from bubble formation to bursting. Meanwhile, the solid holdup distribution and axial particle distribution are related to the upward bubbles, both of which present an asymmetrical distribution for the bubble existing region. However, the holdup distributions present a symmetrical distribution similar to the packed bed for the non-bubble region. The results could make up for the deficiency of the experiments effectively and reveal the high-density gas–solid countercurrent flow mechanism comprehensively.