Because of coal price is more and more expensive in China, coal-fired power plants use low quality coals deviated from the designed grade in order to reduce costs, which will lead to the boiler pulverizing system output is limited, the security and the economic performance is decreases. The coal applicability for pulverizing system in 1 036 MW coal-fired units boiler was investigated based on the experimental research to obtain the maximum output of coal mill using different coals. This paper adjusted the wind-coal ratio of coal mill and proposed some suggests, such as it should do regular calibration for primary air flow, and the calculation of minimum running air flow should consider the moisture, viscosity and other parameters of coal.