Based on the analysis of high-speed cutting principle, the numerical simulation of a flow field within the crushing chamber in pulverizing process was performed by CFD technique, and Fluent software, in which RNG k-ε turbulence model was adopted. The effects of impeller blade shape, blade angle and impeller speed on the flow field were revealed, and the crush velocity, pressure, and shear strain rate were analyzed. The linear relationships between the impeller speed and various parameters were obtained. In case of straight blade impeller with 2° deflection angle the obtained flow field shows the optimal efficiency for cutting crush. The experiments for various materials indicate that the high-speed cutting grinder has the broad prospects with physical adaptability and smashing effect.