The mineralogical name of bentonite is montmorillonite, and natural bentonite is mainly divided into sodium and calcium based on chemical composition. Bentonite has the property of swelling with water. Generally, when calcium bentonite expands, its expansion is only about 3 times its own volume. When sodium bentonite expands, it is about 15 times its own volume and can absorb 6 times its own weight. Water, the high density colloid formed by such expanded bentonite has the property of repelling water. Using this property, sodium bentonite is used as a waterproof material. In order to facilitate construction and transportation, the bentonite is locked in the middle of two layers of geosynthetic materials to protect and reinforce the GCL bentonite waterproof blanket with a certain overall tensile and puncture strength.