Background <p>Ultra-thin glass (UTG) has been widely used in high-tech applications due to its flexibility and optical transparency, however, post-processing operations introduce micro-cracks and residual stresses that compromise bending strength. Conventional bending strength definitions often fail to capture actual fracture behavior caused by surface flaws and nonuniform stress distributions.</p> Objective <p>This study aims to develop a general experimental–analytical approach for full-field bending stress evaluation of UTG under two-point bending conditions, capable of accurately describing large deflection behavior and stress evolution along the entire bent profile.</p> Methods <p>Advanced large deflection beam theory (A-LDBT) was applied to the two-point bending configuration, with the horizontal compression distance serving as a single control parameter. A quadratic representation of the deflected beam profile was used to derive the tangent angle along the neutral axis and calculate the full-field bending stress. The analytical profile was verified against bent profile images, while three-dimensional digital image correlation (3D-DIC) provided full-field strain measurements under various compression distances.</p> Results <p>The deflection beam profile equation successfully determined the geometric parameters, and experimental strain distributions agreed well with theoretical predictions from A-LDBT. Despite setup limitations, 3D-DIC captured local strain fields at critical bending locations. The measured strains enabled direct evaluation of bending stress without relying on contour extraction or repeated curve fitting.</p> Conclusions <p>The results demonstrate that combining A-LDBT with 3D-DIC provides a reliable method for full-field stress evaluation of UTG under two-point bending. By removing previous contact angle restrictions, the approach extends the measurable deformation range and enables effective assessment of stress and mechanical reliability in UTG substrates.</p>