Abstract: After the increase of clinker production, there are some problems in the kiln inlet chamber, such as small cross-sectional area of ventilation, high gas velocity, large resistance and secondary dust of materials entering the kiln. By adopting measures including expanding the volume of the flue gas chamber and adjusting the slope angle, the negative pressure of the flue gas chamber is reduced by 200 Pa, the output of the kiln system is increased by 200 t/d, and the standard coal consumption of clinker burning is reduced by about 0.92 kg / t, the economic and social benefits are remarkable.