Abstract: Orthogonal experiments were carried out on the coal pulverizer of a 1 100 t/h boiler, so as to study the effects of following factors on both the pulverized coal fineness and unit power consumption, such as the coal feed rate, primary air flow and the separator rotating speed, etc. Meanwhile, the affection degree of above 3 factors on the pulverized coal fineness and unit power consumption was determined, based on which an optimum operation mode was found for the pulverizing system. Results show that the coal feed rate and separator rotating speed greatly affect the pulverized coal fineness and unit power consumption. To ensure a safe and economic operation of the pulverizing system, the operating parameters should be adjusted after a certain period of operation. The fit curves of this study may serve as a reference for actual operation of similar pulverizing systems.