We developed an eco-friendly method to facilely prepare the good-formability methyltrimethoxysilane (MTMS)-based silica aerogels via water solvent system and ambient pressure drying in one-step. In the whole procedure, water was used not only as a reaction agent but also as a solvent, avoiding the expensive cost and environmental pollution caused by solvent exchange. The structural properties of MTMS-based silica aerogels were characterized by the scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller methods. The results indicated that compared with other silica aerogels prepared by traditional water solvent methods, this MTMS-based silica aerogels had the classic nanostructure with the high specific surface area of 450 m2/g as well as hydrophobic property.