Abstract: In the process of float process, the contact between glass melt and tin liquid leads to the phenomenon of tin infiltration on the lower surface of glass plate, which affects the performance and processing quality of glass products. Therefore, based on the chemical composition of low aluminum glass, the electron probe microanalyzer (EPMA) was used to scan the cross section of the glass sample through the tin penetration simulation experiment, the penetration depth of tin ion was measured, and the effect of alkali earth metal oxide (CaO, MgO) and redox value of glass mixture on the penetration depth and peak concentration of tin ion was studied. Results show that MgO has a better effect on the inhibition of penetration depth than CaO, mainly because of the strong Mg-O bond, which hinders the exchange rate of R⁺ and Sn²⁺ ions. With the increase of the redox value, the peak concentration of tin permeation on the surface of glass increases. When the redox is positive, it is favorable to the oxidation reaction of tin element to generate Sn²⁺ and Sn⁴⁺, creating a bar for the exchange of Sn²⁺ and Sn⁴⁺ with alkali metal ion R⁺ in glass melt.