This paper introduces the advantages and disadvantages of each technological process of the bypass system at the kiln inlet chamber of cement kiln under different dust capture methods, as well as the selection of venting volume and its specific design requirements when designing the bypass system. When the bypass ratio is less than 25%, the flue gas intake point should be set at the center on the side of the rotary kiln; the pipeline before entering the quenching chamber generally needs to be set with castable in a thickness of 230mm; the gas speed at the inlet is generally designed at 20m/s, and the gas speed at the air outlet is generally set at 18m/s. The length of the flue gas pipeline from the quenching chamber to the air inlet of the dust collector would be more than 20m.