The flow of gas and solid particles in DD-precalciner in the cement plant with capacity of 5000t/d was studied by numerical calculation using Fluent software. The DD-precalciner includes four eccentric burners, two eccentric tertiary air ducts and four feed boxes. The standard k-ε model was proposed to simulate the three-dimension turbulence flow and the movement of solid particles was simulated by particle stochastic trajectory model. The speed contours and velocity vector of different sections as well as the trajectories of solid particles were calculated and analyzed. It indicates that the structure design of DD-precalciner can great improve the combustion of coal power and decomposition of CaCO3 particles.