The structure of CaO–SiO2–Al2O3–TiO2 glass has been characterized using Raman spectroscopy for further preparation of CaO–SiO2–Al2O3-based glass-ceramics. After verifying the depolymerization effects of superheat on the network structure, the effects of TiO2 on the structure have been examined under the condition of excluding the influence of superheat. TiO2 is found to mainly form the [TiO4] tetrahedron and [TiO6] octahedron, with [TiO4] being dominant. Increasing TiO2 increases the proportion of TiO44− and SiO44− monomer, [TiO6] as well as the O–Ti–O deformation, and decreases the proportion of total SiO32− and Si2O52−. Although the mole ratio of Q2 to Q3 decreases with increasing TiO2 and a part of TiO2 participates in the formation of a sheet structure with silicates, the degree of polymerization of the system still decreases overall, because the increased TiO2 is more favorable to form the monomer structure and a large amount of increased TiO2 forms the monomer structure. The obtained structural characteristics with consideration of the superheat are more accurate and the method of studying structural characteristics of glass proposed by this work is of more practical significance.