Covered yarn is a kind of high performance textile material, which is usually made of one or more fibers as covered fibers and wrapped around the yarn core. Different types of covered yarn have different composition of yarn core and covered fiber. For example, the core of the special covered yarn can be composed of glass fiber and nylon fiber, and the external covered fiber can be one or more mixtures of polyester fiber, nylon fiber, viscose fiber, and bamboo fiber; Spandex covered yarn is made by wrapping spandex fibers on the surface of the yarn.