There are large shopping malls selling cotton trousers, clothing stores, Taobao, Pinduoduo and other online channels. Cotton trousers refer to trousers made of cotton, chemical fiber, camel hair and other warm materials, including baby foot-wrapped styles, children dustpan trousers, adult slim elastic trousers, and split trousers for the elderly. This kind of trousers generally has three layers, the outermost layer is the face, the cloth is thicker and the color is bright; The innermost layer is lining, and the cloth is mostly light cotton cloth; In the middle is warm cotton. With the development of the times, the wadding in the middle is no longer limited to natural cotton, but also can be space cotton, chemical fiber cotton and other warm materials.