A type of aluminosilicate that has a good wetting property for molybdenum disilicide (MoSi2) was added to a MoSi2 matrix to study the effects on the microstructure and low-temperature oxidation. It was found that the composites had not only good low-temperature oxidation resistance but also high thermal shock resistance when the added oxides formed a network microstructure in the matrix. There was no appreciable oxidation gain for MoSi2/oxide composites with a network microstructure at 773 K for 2500 h. The results indicate that microstructure design is a simple and effective solution to preventing the low-temperature oxidation of MoSi2.