The invention provides a seepage-preventing and water-stopping structure for water conservancy projects and belongs to the field of water conservancy projects. The seepage-preventing and water-stopping structure comprises a long-strip-shaped box body; a long-strip-shaped containing cavity is formed in the lower portion of the box body; a water-proof film coil is arranged in the containing cavity,and the containing cavity is provided with a long-strip-shaped opening for communicating with the outside world; long-strip-shaped clamping strips which are detachably connected with the top of the box body are arranged at the top of the box body; and the clamping strips are provided with clamping parts which can clamp the ends of water-proof films. In the water conservancy construction process, the seepage-preventing and water-stopping structure is laid in the soil surface where water and soil erosion is prone to occurring, and through the seepage-preventing and water-stopping effects of thewater-proof films, water and soil are conserved; and the structure is convenient to construct and easy to carry, and can be applied to the water conservancy projects on a large scale, and thus the construction efficiency of the water conservancy projects is improved.