A new particle-based simulation model to tackle the problem of micrometer scale particle motion in sedimentation at low to high concentration is presented. In this model, the solid particle interactions are described by discrete element method (DEM), while the liquid part are simulated by a mesoscale fluid simulation method dissipative particle dynamics (DPD). The coupling part are modified DPD potential with tuned parameters to ensure the correct hydrodynamic interaction between solid and liquid particles. Experiments are further conducted to compare the simulation phenomenon. The well agreement verifies the presented coupling is an effective model for this scenario. Some new results for sedimentation of different initial conditions, such as liquid volume, and particle size are then presented. This new model can be a powerful tool to simulate micrometer particles sedimentation process, which is important in material design and quality control of sedimentation based FGM manufacture.