To discuss optimum parameters of substances participating chemical reaction in industry reaction tower, and some mechanism of reaction process, it is necessary to understand information of particle crowd in reactionary process. For example, we can obtain size parameter,distribution parameter and SM1) from size and distribution information of crowd particles. In order to know optimel reaction effect in high speed centrifugal spray field, it is very important to measure particle size and distribution in atomized field. That requirs an instrument, whose measurement principle should be right and can work well under severe atomized field circumstance. This paper describes the principle of such an instrument ,analyses work-site environment and takes some relative measures to ensure measurement, give the measure results at work- size, and finally proposes atomizing quality problem.