The apparent viscosity, viscosity-flow activation energy and non-Newtonian viscosity of polyvinyl butyral (PVB) were determined by RS150 plate rheometer. The apparent viscosity of PVB water-resistant resin was studied at different shear rates. In this paper, PVB waterproofing agent is used for laminated glass. The bending resistance of PVB waterproof laminated glass is studied. Two different failure forms are summarized: failure forms in steel bars and floating laminated glass. The effect of the PVB waterproof intermediate layer in the test process is compared. The results show that the laminated glass does not have good bending toughness when the thickness of the intermediate film is less than 0.38 mm. The surface viscosity of PVB water-resistant glass decreases with the e-temperature increase. With the increase of shear rate and shear force, the apparent viscosity of PVB waterproof adhesive decreases gradually. Its Newtonian coefficient is less than 1. And it increases as the temperature increases. It indicates that the water-repellent PVB type exists in the form of a pseudo-plastic liquid. The flexural characteristics of various types of PVB waterproof laminated glass are studied. The chemical composition of the PVB water-resistant material sample was analyzed after bending failure. Based on the comparison of component ratio and molecular weight and the conceptual theory of polymer chemistry, the root cause of the failure was explained.