The invention discloses a cotton-covered spandex T400 twin-core elastic series shell fabric. Polyester T400 fibers serve as core yarn, cotton fibers serve as fasciated yarn, cotton-covered spandex T400 twin-core elastic yarn integrates all characteristics of the cotton fibers, spandex and T400 fibers to make up deficiencies, the shell fabric has ultrahigh elasticity and ductility of the spandex and excellent heat resistance, fatigue resistance and oxidization resistance of the polyester T400 fibers, and after the outmost layer is wrapped by the cotton fibers, the shell fabric has hand feeling and a moisture absorbing property of the cotton fibers.