The invention discloses a water retaining device with a decorative curtain, and relates to the technical field of flood gates, the water retaining device specifically comprises a base, a water retaining panel and a flexible sealing element, the rear end of the water retaining panel is hinged to the base, and the front end of the water retaining panel can be rotatably opened for water retaining; the flexible sealing element is arranged between the side wall and the panel and is used for sealing between the side wall and the panel; the flexible sealing piece further comprises curtain cloth and a hoisting mechanism used for hoisting the upper end of the curtain cloth, the upper end of the curtain cloth is fixed to the hoisting mechanism, and the hoisting mechanism is installed on the portion, above the flexible sealing piece, of the side wall. According to the flood gate, through the design of the expandable curtain cloth, when the water retaining panel of the flood gate is closed and does not block water, the curtain cloth is expanded to cover the flexible sealing piece, so that people cannot directly observe the flexible sealing piece, the overall attractiveness is improved, the aging process of the flexible sealing piece is slowed down, and the service life of the flexible sealing piece is prolonged.