A double-layer container includes an outer layer and an inner layer, both of which are formed by molding. The outer layer includes a 3-D pattern. The 3-D pattern has at least two pattern units each having at least one first groove which communicates with at least one through hole. The through hole is defined through the outer layer. At least one first slot is defined between the pattern units. The inner layer is fixed to an inner surface of the outer layer and the material of the inner layer is filled in the first groove via the through hole to form a first decoration portion.