Abstract: One circulating fluidized bed pyrolysis process of pulverized coal that couples the gasification of char was proposed. In order to achieve the physical zoning between pyrolysis and gasification inside the riser, cold-state experimental research was conducted on a circulating fluidized bed test rig. Through analyzing the pressure drop distribution inside the riser with a multi-section variable-diameter structure, the conveying and settling characteristics of the riser with such special structure were studied. It is found that the whole conveying process of solids can be divided into three stages: particle fluidization, particle conveying, and particle conveying completion. For the effective conveying of solids, the fluidization number in the lower isodiametric section shall be above 47.6. The middle-necking and upper-expanding structure of riser exhibits an excellent anti-settling performance. Only at the fluidization number below 25.2, the settling of solids in the upper-expanding section to the lower occurs. The gas expansion caused by multiple factors during the actual operation will enhance the conveying capacity of particles, making the achievement of effective conveying process at a lower airflow velocity. In this case, the particles inside the upper-expanding section are more prone to backmixing, resulting in the formation of local dense phase zone. This study will provide a theoretical basis for the design and optimization of the novel circulating fluidized bed pyrolysis reactor of pulverized coal.