Polymer modified asphalt composite flexible waterproof roll material refers to a waterproof roll material made from two types of composite felt as the base material, rubber, resin and other polymer modified asphalt as the base material, and fine sand, mineral particle (sheet) material, polyester film, polyethylene film and other covering materials, using immersion coating, rolling and other processes. Compared with asphalt rolls, this type of product has a significant improvement in flexibility. Using composite felt as the substrate, the tensile strength of the roll is higher than that of the single polyethylene film substrate. This type of product has been released as the JC/T 690-1998 building materials industry standard.