Recently, a novel lightweight cork with enhanced thermal stability has been prepared using a respiratory impregnation method. In this paper, the thermal stability and decomposition of two kinds of cork CS-P (Quercus suber) and CV-P (Quercus variabilis B1) and corks that infused silica aerogel in cells CSS-P (Quercus suber) and CSV-P (Quercus variabilis B1) were systematically studied, and their decomposition mechanisms were proposed. The results showed that the decomposition was inhibited at 200 °C, and the pyrolysis was significantly inhibited at the main pyrolysis stage (400 °C). Interestingly, the evolved gaseous products and their evolution models have also changed. Specifically, CO2 and aldehyde emissions were significantly reduced in the main pyrolysis stage, reducing environmental pollution. Silica aerogel filler plays a catalytic role in the pyrolysis process, thus increasing the output of some value-added products (such as aromatics), which is suitable as the appropriate raw material or source of olefins to produce aliphatic rich pyrolysis biofuels. In general, the yield of biochar and bio-oil can be adjusted under low environmental pollution by loading silica aerogel and adjusting pyrolysis temperature. Corks that infused silica aerogel in cells may be a promising raw material for the production of biochar and biofuel through pyrolysis and contribute to the environmental and economic sustainability of the cork production industry.