There are two key technical problems needing to be solved in the design of airflow crusher. First,the crushing energy should be consumed maximally in the insrease of superficial energy to improve the output rate;second,the overflow of the big particles should be prevented effectively and the size of product should be strictly controlled. According to the theory of flow field and the results of tests,the author analyzes and puts forward an effective way to solving these problems. In addition, a detail introduction to the crushing priciple of JM model airflow crusher,the process flow and the basis of determining the main technical parameters is made. The rasults of practical use has shown that JM model airflow crusher is the most effective equipment for the preparation of superfine powder.