Cotton yarn is generally used as loop yarn, velvet plump, soft feel, comfortable to wear, beautiful and generous. Velvet products require high grade, low linear density, long length and good maturity of fine and long velvet quality cotton. Velvet products have special requirements for the twist of loop yarn. When cotton yarn is used, it is required that the twist of cotton yarn is smaller and the twist irregularity of cotton yarn is smaller. At the same time, when knitting velvet fabric, the ground yarn should be arranged in two different twist directions, while the terry yarn should be arranged in the same twist direction, which will help to improve the velvet quality and handle.