The composite geomembrane has corresponding anti-cracking and anti-piercing capabilities, but when the water head is relatively large, the sharp gravel and tree roots under the film will usually crack. During the anti-seepage construction of Wanxiuqiao Reservoir, the dry masonry and sand gravel cushions on the original dam surface were excavated to the clay layer, and the slope was excavated according to the size of the design plan, backfilled and tamped under the slope, leveled and watered, The dry bulk density is not less than 1.65t/resistance. Manually excavate non-slip grooves, clean up surface rocks, tree roots and other solid and sharp objects, and spray herbicides and other drugs. The finished slope should be leveled, compact and smooth to avoid the composite geomembrane being penetrated. After the flatness requirements of the design plan are realized, the engineering inspection and acceptance by the supervision engineer is used as the composite geomembrane paving face.