To enhance heat transfer, as well as prevent and remove fouling, a two-pass circulating fluidized bed evaporator with baffle has been designed and built. The uniformity of particle distribution significantly influences the performance of evaporator. This paper mainly researches the influences of particle types on the particle distribution with a Charge Couple Device image measurement and acquisition system. Consequently, for four kinds of partides, partide distributions in the up-flow bed are relatively uniform; those in the down-flow bed become more uniform with the increase of circulation flow rate and decline of partide amount and baffle height Partide maldistribution becomes obvious with the increase of partide density. Furthermore, particles with greater density are more susceptible to the operating parameters, and the increase of circulation flow rate can weaken the influences of partide amount and baffle height. Finally, phase diagrams are established to show the optimal range of the operating parameters. (C) 2020 Elsevier B.V. All rights reserved.