Film waterproof blanket is a kind of waterproof material. It is made of attaching a layer of geomembrane on bentonite waterproof blanket. It also can prevent infiltration and solid foundation in tunnel, lake, highway and some other underground constructions, just like bentonite waterproof blanket. But the impermeability performance of film waterproof blanket is much better than the bentonite waterproof blanket. In addition, film waterproof blanket is made of environment protection material. So it is not only can prevent corrosion and aging, it also will not harm the human body and the environment.