An allergen-barrier bedding cover made of polyurethane coated cover fabric, which is waterproof yet permeable to water vapor, reduces contamination of bedding, and blocks dust mites and other allergens, and can be washable. The outer face of cover fabric is non-allergic cotton, nano fiber, or Lyocell, and the inner face of cover fabric is coated with polyurethane. The closure is formed with a zipper, of which the back is coated with polyurethane in order to seal the needle holes of the seams sewing zipper tapes and teeth together, and the gap between teeth is less than 0.01 mm to prevent dust mites from passing through it, and the width of the zipper chain is less than 4 mm. A patch coated with polyurethane is attached inwardly at the end of the zipper, where the zipper is closed, to prevent dust mites from passing through the zipper slider. The needle holes of the seams not only between cover fabrics but also between cover fabrics and zipper tapes of the closure are sealed with seam sealing tapes. The allergen-barrier bedding cover prevents the cause of allergy and keeps the sleep environment clean and hygienic.