Silica aerogels have the characteristics of low density, high porosity, high specific surface area and low thermal conductivity, but they have some defects such as low strength and poor toughness. On this basis, flexible silica aerogels show better mechanical properties and applicability by improving the preparation process of traditional silica aerogels. This paper reviews the latest research progress of flexible silica aerogels from home and abroad and compares the performance parameters of different types of aerogel. The commonly used preparation methods, such as precursor modification, polymer modification and fiber reinforcement, are introduced emphatically. And the precursor modification method is easier to realize the design of microstructure and properties of aerogel materials by selecting and combining the types of silicon sources, which is considered as the primary method for preparing flexible silica aerogels and the research hotspot at present. In addition, its applications in the fields of thermal insulation, oil-water separation, and high efficiency sound insulation are summarized and the development of flexible silica aerogel is prospected in this article.