A series of (CaO-SiO2)-xAl2O3 (x=0, 6, 12, 18, 24, 30) glasses were successfully prepared in a pneumatic suspension device, and their structures were qualitatively and quantitatively studied by Raman spectroscopy, quantum chemistry ab initio calculation and 27Al MAS-NMR. It shows that when the basicity R (CaO/SiO2)=1 , Al mainly participates in the network formation in the form of ［ⅣAlO4］ by x≤18 and reaches the maximum when x=18. At the same time, the existence of ［ⅤAlO5］ and ［ⅥAlO6］ is also observed; When x>18, the relative content of ［ⅣAlO4］ decreased, while ［ⅤAlO5］ and ［ⅥAlO6］ increased. The results of Raman fine resolution spectra show that the addition of Al greatly increases the complexity and disorder of the structure, which is manifested by the irregular change of the content of fine structure Qijklm, but has little effect on the content of primary structure Qi which mainly exists in the form of Q2.