Abstract: Granular flows are pretty common in natural phenomena and industrial applications, such as landslides, pebble-bed reactors and the gravity-driven dense granular flow target (DGT) in accelerator driven sub-critical system (ADS). Based on the μ(I) rheology model, a material point method (MPM) procedure was chosen for the simulation of the dense granular flow. By using the MPM framework, the granular collapse problem and the hopper flow were investigated. The method was verified by experimental and DEM results. The result shows that the modeling and numerical approach described in this article can capture the granular solid and fluid behavior and could be extended to more complex industrial applications.