Abstract: Based on modeling and simulation on traditional resistant heating sintering, through analyzing the microwave sintering mechanism of powder injection molding materials, and together with the principles of electromagnetic fields, thermodynamics and continuum mechanics, the mathematical models and simulation methods for describing microwave sintering process were determined. By means of a reasonable mathematical model and governing equations, the microwave sintering process was simulated in the platform of finite element software COMSOL Multi-physics. The simulation results were compared with experimental ones. The results indicate that zirconia powder molding sample was heated slowly in the initial stage until temperature up to 400 ℃, and then temperature increased dramatically. When heated to the peak temperature of 1 360 ℃, the relative density of the sintered sample was up to 92%, which satisfied the requirement for powder sintering. The built mathematical model is conformed to be valuable to simulate the evolution of electric field, temperature field and the densification process of powder molding materials during microwave sintering.