The temperature difference between two sides of tempered vacuum glass is one of the important reasons for its bending failure. The deformation characteristics of tempered vacuum glass (TVG) were tested at various temperature difference and in various diameters, and determined by temperature difference deformation tests and finite element modelin (FEM) analysis. The findings demonstrate that the maximum deformation of TVG is in the center of the glass and gradually decreases to the periphery. Curvature radius of the sphere created by temperature difference between two sides of TVG is directly proportional to the thickness of the tempered glass, but inversely proportional to temperature difference between the two sides as well as to the linear expansion coefficient of glass. Glass size, temperature difference and curvature radius are all positivly correlated with the deformation of TVG. With the same temperature difference and different size of TVG, its deformation increases with the increase of the long side size of tempered glass. The larger the long edge size of TVG, the more significantly the deformation is affected by temperature difference. Moreover, a useful approach for the deformation prediction of TVG with different diameters under temperature difference is provided by the FEM analysis results, which is in good agreement with the experimental findings and where the relative error is less than 5%.