Double-cover covering yarn

The utility model discloses a double-cover covering yarn which is characterized by comprising a core layer, a functional fiber layer and an outer yarn-covering fiber layer successively arranged from inner to outer, wherein the core layer has a double-core structure which is composed of a PTT/PET compound filament and a spandex filament; the functional fiber layer is composed of a silver-covered antibacterial fiber; the outer yarn-covering fiber layer is composed of a tencel fiber. The double-cover covering yarn has the advantages of excellent repeated fatigue resistance elasticity, size stability, soft hand feel and excellent antibacterial property.