Hemp is a fiber obtained from various hemp plants, including the bast fiber of the cortex of annual or perennial herbaceous dicotyledonous plants and the leaf fiber of monocotyledonous plants. Bast fiber crops mainly include ramie, jute, green hemp, hemp, flax, apocynum and hone. Among them, hemp, flax, apocynum and other cell walls are not lignified, and the thickness and length of the fibers are similar to cotton. They can be used as textile raw materials to weave into various cool linen and linen cloths, and can also be blended with cotton, wool, silk or chemical fibers; Bast fibers such as jute and kenaf have lignified cell walls and short fibers, so they are only suitable for spinning ropes and packaging sacks.