The invention relates to a movable formwork for single rectangular top closed type water conservancy aqueduct construction. The movable formwork comprises an outer beam system, an inner beam system and a hoisting system, wherein the outer beam system comprises an outer beam, an outer rib, an outer formwork, a No.1 landing leg, a No.2 landing leg, a No.3A landing leg, a No.3B landing leg and No.4 landing leg; the No.2 landing leg, the No.3A landing leg and the No.3B landing leg are matched with each other so as to move the outer formwork under the driving of a girder; the inner beam system comprises an inner beam, an inner beam holding support leg, an inner beam walking support leg and an inner formwork; the inner beam has a single girder truss structure; the inner formwork is driven to move by the inner beam walking support leg; the hoisting system comprises a hauling mechanism and a hoisting mechanism; the hoisting system can drive the landing leg to move to an effective construction position. According to the invention, in the manner of striding the outer beam for a half of length, positioning the No.3B landing leg on a groove surface while pouring, driving the outer beam to walk by the hydraulic system and punching twice, the punching manner is more stable and safe and the structure form and construction mode are different from those of the previous water conservancy aqueduct machine.