Due to the fragility， hydrophilicity and high cost， the application of aerogels in civil fields is limited. In this paper， the flexible and hydrophobic polysilsesquioxane aerogel has been prepared using dimethyldimethoxysilane （DMDMS） and vinyltrimethoxysilane （VTMS） as co-precursors through atmospheric pressure drying. The effects of different silicon source ratios on the structure and properties of aerogels were studied. When n （ DMDMS/VTMS ）=2∶3， the silicon-based aerogel exhibits a three-dimensional nanoporous structure， which has low density （0.13 g/cm³）， low thermal conductivity ［2.919×10^-2 W/（m·K）］ and superhydrophobicity （151°）. Its maximum stress shows no significan change after 500 compression cycles under 50% deformation . According to this simple preparation process， the flexible aerogel has promising application prospects in the field of thermal insulation.