Glass, a fragile material that gains popularity in building construction, has been developed to sustain with high loads. This structural glass would not work effectively if the connection has not been able to transfer the loads properly. The study aims to optimize bolted connection of structural glass. We focus on the geometry optimization of the bolt to deal with heavy external loading that requires a strong connection. Numerical parametric studies are conducted by investigating four factors: material of insert, shape, diameter, and material of bolt, which play roles on stress distributions at glass-bolt contacts. The insert made of materials softer than glass and steel improve the initial contact condition. Shapes of bolt change not only its stiffness but also location of stress concentration. Larger diameter and higher elasticity of bolt can develop stiffness increasingly that could reduce stress concentration as well. Based on the numerical parametric studies results, we can choose an effective geometry, which provides a connection with high load resistance.