Glass-alumina bi-layer composite was widely used as dental materials, the reliability and mechanical properties are very important for its practical application. In this work, residual stresses in dental glass-alumina composite and failure mechanism were investigated through finite element analysis and 3-point and ball-on-ring bending tests, respectively. The mechanical behavior of the dental material was studied using the bending tests and indentation method. Small bi-layer disk specimens were prepared for the axis-symmetrical tests using a set of small device in a universal tester. The results indicate that the difference in thermal expansion coefficients between two layers lead to residual stresses in both layers, and the stresses distribution depends on the thickness ratio and temperature difference. Furthermore, a proof testing method was proposed to estimate the workability and reliability of the dental ceramics.