The utility model relates to a scalable water containing ware that holds of closed, including the retaining inner bag, adopt fluid -tight material to make, the roof, the roof is inflexible, establishes retaining inner bag upper end and with retaining inner bag sealing connection, be equipped with the inspection hole on it, be equipped with sealed apron on the inspection hole, be equipped with discharge valve on the sealed apron, the bottom plate, the bottom plate is inflexible, establishes retaining inner bag lower extreme and with retaining inner bag sealing connection, set up water inlet anddelivery port on it, inflexible retractable safety cover, the safety cover is located around the outside of retaining inner bag. The utility model discloses a retaining inner bag adopt have elasticity compressibility have again certain bearing capacity material producing can, as long as the weight of calculating out required roof according to the elastic modulus and the pressure gage in the retaining inner bag of material can, easily design, preparation and installation, and reasonable in design, simple structure uses safe and reliable.