Investigation of complicated particle-motion behaviors are of paramount importance for dual circulating fluidized beds (DCFBs), which are promising industrial reactors. On the basis of our pervious experiment [Geng et al. Powder Technol. 2016, 304, 81], a multiphase particle-in-cell (MP-PIC) scheme was carried out to investigate the gas-solid-flow behaviors in the DCFB. Meanwhile, the turbulent gas and solid phases were simulated by the large-eddy simulation (LES) and the discrete-particle method, respectively. The particle-motion behaviors that are difficult to ascertain by experiments (e.g., particle velocity and distribution) were numerically investigated. The results show that open overflow has an insignificant effect on the full gas-solid circulation in the state of CFB. An increase in initial bed inventory or riser-aeration rate will lead to obvious increases in solid concentration. In addition, particle motion in the symmetric and asymmetric couple flow was also investigated.