Abstract: An new type of entrained slagging pulverized coal combustor is developed based on cold state model experiment, the velocity distribution and mixing process in the combustor are researched. The results of the experiments show that for the axial velocity distribution, 6 different zones can be found, 4 of which are reverse flow zones. Annular reverse flow zone can be found too in the combustor with the flat-straight slag baffle. The flat-straight slag baffle can replace the cone-convergent one in the design of cyclone combustor. The optimum parameters are that the swirl number of primary air is 1.78 to 2.0, the ratio of primary air is 15% to 20%, the distance between primary air inlet and the secondary one is (0.75-1.15)D.