The CFD-DEM is widely used in numerical simulation of fluid beds

but restricted by computing workload of DEM

it is difficult to meet the requirements for simulation of actual fluidized beds.Therefore

conducting researches on parallel algorithms for DEM is particularly important.According to the characteristics of particle motion in the fluidized bed

parallel computing model of particle- phase in gas solid twophase flow based on the method of DEM was established

which can achieve the parallelization between force calculation of particles and update for velocity and location of particles on the basis of the OpenMP parallel technology.A 3-D parallel DEM code for simulating the particle deposited process in a fluidized bed was developed based on the OpenMP standard in this paper.The computation results which used parallel program were compared with that used serial program.The results of parallel program show that it has a better speedup than the serial program

and the computational efficiency is improved greatly with the parallel program.As the number of threads increasing

the speedup ratio increases gradually

while the increase rate is relatively reduced.