The invention discloses a three-cavity sterile bag and a preparation method thereof. The square sterile bag consists of a double-cavity inner bag and an outer packaging bag, wherein the double-cavity inner bag is formed by
welding horn-shaped liquid filling ports, arc-shaped insufficient
soldering strips with opening points,
thermal transfer with independent cavities, hanging holes, an A liquid medicament cavity, an intermediate liquid medicament cavity, a C liquid medicament cavity, three-cavity bag sides, three-cavity bag corners, straight-strip sealing grids, a medicament delivery plug and a medicament feeding plug into a whole through heat seal; and one side of the outer packaging bag is provided with an outer packaging bag
welding edge and an outer packaging bag opening mouth. The preparation method of the sterile bag comprises the steps of bag molding, preparation of filling junctions of the bag, filling, lamp inspection, packaging and sterilization. The three-cavity sterile bag is simple in structure and easy to operate; and for the insufficient
soldering of the bag, scientific external force opening points are designed, so that the insufficient
soldering of the bag is more operable.