The invention relates to a feather and down sorting instrument and a working method thereof. The instrument comprises a sorting barrel in which an airflow generating device is arranged, wherein a feather and down mixture in the sorting barrel is rotated by layers through the airflow generating device; an absorbing device is positioned at the upper part of the sorting barrel and is used for absorbing the down and the leather by layers when a down layer or a leather layer reaches the absorbing device according to the height. According to the feather and down sorting instrument, the down and leather mixture is driven to quickly rotate through rotating airflow in the sorting barrel, and the down and the leather are layered during being rotated; the down is absorbed under negative pressure through the absorbing device and collected through a collecting barrel; then the leather is absorbed by adjusting of an end cover and an air pore adjusting mechanism and is collected through another collecting bag; in addition, the feather and down sorting instrument has the advantages of being simple to operate, and high in sorting purity.