Silica aerogel is an attractive thermal insulation material due to its low thermal conductivity, light weight and non-combustible inorganic properties, but its inherent brittleness and high production cost hinder its practical application on a large scale. Herein, the high-performance pre-oxidized polyacrylonitrile fiber composite silica aerogel felt (PPAF-SiO2) was successfully prepared by a cost-effective combustion drying technique for the first time. The results show that the PPAF-SiO2 has the feature of lightweight, good flexibility, and its heat resistance, hydrophobicity, and specific surface area are significantly improved. Due to the further polymerization of fiber structure molecules caused by combustion, the tensile strength of the PPAF-SiO2 is increased by 81.9% to 1.71MPa. More importantly, due to the high proportion of silica aerogel in felt, its thermal conductivity can be reduced to 0.02W/(m·K), which is lower than most aerogel composite materials. Moreover, the thermal insulation performance of the PPAF-SiO2 was further confirmed by the infrared thermal imager from room temperature to 300 ℃. In addition, the innovative drying mechanism based on the combustion flame model was proposed. Finally, compared with traditional physical drying technologies in terms of drying time and drying conditions, the combustion drying technology shows great advantages in drying efficiency, energy consumption and equipment investment, which greatly reduces production costs. The combustion drying technology opens up a promisingly method for high efficiency, low energy consumption, and low cost preparation of silica aerogel composites.