Wool is mainly composed of protein. Human use of wool can be traced back to the Neolithic age, from Central Asia to the Mediterranean and other parts of the world, and became the main textile raw material in Asia and europe. Wool fiber is soft and elastic, can be used for the production of wool, wool, blanket, felt and textiles. Wool products have the features of full feel, good warmth retention and comfortable wearing. Sheep wool occupies a large proportion in textile raw materials. The world's sheep wool production is larger in Australia, the former Soviet Union, New Zealand, Argentina, China and so on. Sheep wool is divided into 5 categories: fine wool, semi fine wool, long wool, hybrid wool and coarse wool according to fineness and length. Chinese sheep breeds include Mongolian wool, Tibetan wool and Kazakh wool. The main factors that determine the quality of wool are fineness, crimp, color, strength and grass impurity content.