The direct firing pulverizing system is dominant in the coal pulverizing system of large-scale coal boiler. The performance of pulverizing system is discussed matching with 2×1 000 MW ultra-supercritical boilers of a power plant. The speed characteristics of the dynamic separator, the adjustment test for grinding roll loading pressure and mill capacity characteristics are analyzed. Furthermore, the effects of mill outlet temperature, ventilation rates and grinding bowl differential pressure on mill capacity are investigated. As a result, the economic operation parameters for the coal pulverizer are obtained, that could enhance the output, reduce the single consumption and improve the running economy of the units under proper coal fineness and uniform index.