Spinel glass-ceramics exhibit excellent mechanical properties and high permeability, making it highly suitable for various applications such as cover glass, aerospace, military, dental and optical devices. The effect of ZnO content on the crystallization behavior and properties of MgO-Al2 O3 -SiO2 (MAS) glass was investigated. The results show that the increase of ZnO content leads to a gradual decrease in the glass transition temperature. Additionally, the crystallization peak temperature shifts to lower temperatures, accompanied by an increase in the crystallization peak magnitude, which indicates that the addition of ZnO promotes crystallization. The structure of glasses was analyzed by Raman spectroscopy. With the increase of ZnO content, the Q3 , Q3 (Zr) and Q4 units in the glass network gradually decrease, and the Q2 units gradually increase, indicating that the structure of glass network become loose and conducive to the growth of crystals. The addition of ZnO improves the hardness of sample after heat treatment, and the maximum hardness of sample with 7. 5% (mole fraction) ZnO content at 920 ℃ for 2 h is 8. 13 GPa. Moreover, the addition of ZnO enhances the transmittance of hightemperature heat-treated samples. The average transmittance of samples is greater than 80% in the visible light range,which has excellent optical transparency.