Newly developed reactive interatomic potential (ReaxFF) for the Mg/Al/Si/O is applied to operate a series of tensile molecular dynamics (MD) simulations for S-glass. Total 18 number of stress-strain simulations used strain rate from 1e7/s to 5e15/s to all-atom S-glass model. Both strength and modulus converge to specific quasi-static state value as strain rate decreases. Quasi-static modulus of S-glass estimated through extrapolation based on modulus versus strain rate ReaxFF MD data is 88.4 GPa, which is within the range of modulus of S-glass from experiment. Comparing silica and S-glass, normalized non-bonding interaction energy of the S-glass system is less repulsive than silica, which shows the impact of non-bonding interactions on the property of S-glass. This observation matches well with the trend from the binding energy of Mg-BO (bridge oxygen) near Mg-OAl2 and Mg-OAlSi, showing the weak but numerous Mg-BO interaction may play an essential role in stress dissipation against the external force.