<p>This study establishes, for the first time, a quantitative and evolutionary model of the interface contact state between viscoelastic glass and rigid molds during the closing stage of the glass molding process. By optimizing interface design, the formation of local sealed spaces between the glass and mold can be reduced or avoided, thereby improving the molding quality and optical performance of glass products. To address the challenge of directly observing the evolution of interface contact states, a high-fidelity glass molding model based on the finite element method was developed, and an improved “island algorithm” was innovatively introduced to achieve dynamic functionalization and quantifiable representation of interface contact states. This methodological advancement also represents a process innovation in simulating and controlling interface behavior during precision glass molding. Furthermore, the interface contact process was categorized into five typical contact cases, and the mechanisms of sealed space formation under different interface designs were comparatively analyzed. Results indicate that the proposed finite element method combined with the improved islands algorithm can effectively predict and optimize interface contact sequences and reduce the formation of local sealed spaces. This approach is applicable to most axisymmetric optical components and demonstrates significant potential for high-precision glass molding process design and interface structure optimization.</p>