The granular model which is fit for discontinuous bodies is applied to powder injection molding. The powder is regarded as discrete particles which are immersed into binder. The powder three-dimensional flowing in powder injection molding has been simulated based PFC. The results show that the filling rate of granulars is anisotropy and injection molding is always filled in the central region of cavity where resistance is smaller. But the angular area where resistance is large often filled be the end, even if it is close to the center of pressure.