Pressure water storage barrel

A pressure water storage barrel includes a barrel body, a flexible liner bag and a connecting piece, wherein a bag opening is formed on the flexible liner bag, a water cavity is formed inside the flexible liner bag, an air cavity is formed between the flexible liner bag and the barrel body, an air valve assembly communicating the outside and the air cavity and a relief valve assembly communicating a water inlet/outlet and the water cavity are arranged on the barrel body, a through hole is formed in the connecting piece, internal threads are formed at the upper end of the inside of the through hole, external threads are formed outside the relief valve assembly, the upper end of the connecting piece is in threaded connection with the relief valve assembly through the fit between the internal threads and the external threads, and the lower end of the connecting piece is connected with the bag opening. The pressure water storage barrel has the benefits that through the structure that the connecting piece is arran