Polyester covered yarn is a kind of mixed elastic yarn formed by covering the core yarn spandex with polyester in a twists outside. It not only has the characteristics of polyester covering outside, but also has the good elasticity and recovery performance of spandex yarn. Plus, polyester covered yarn makes up for the defects of single spandex or single polyester. Now it is widely used in swimwear, socks, casual wear and other products.