Abstract: The paper introduced normal dedusting methods and their characteristics at present. According to practical situation of a coal preparation plant in Xinjiang, it proposed a design scheme of dedusting system based on PLC, DH+ networking mode and ultrasonic atomization technology with negative pressure, and introduced the system's whole structure, hardware composition, control flow and design of communication program in details. The application result showed that the system has stable performance, perfect dedusting effect, simple operation, high reliability and facility of extending and maintenance.