A highly elastic, flame-retardant, and high-temperature-resistant thermoelectric (TE) aerogel composed of PEDOT:PSS/SWCNT composites was fabricated, demonstrating excellent TE performance and mechanical properties. The aerogel exhibits a high Seebeck coefficient of 38.9 μV/K and low thermal conductivity of 0.074 W/m·K. When compressed, the aerogel shows enhanced TE performance, with a maximum power factor of 0.58 μW/m·K at 80% strain. A flexible TE generator made of 25 connected aerogels can generate a maximum output power of 400 μW at a temperature difference of 300 K, showcasing its high-temperature heat harvesting capability. The aerogel-based sensor can detect a wide range of temperatures (25–325°C) and recognize complex hand motions. A self-powered wearable sensing glove was developed for wide-range temperature detection and hand gesture recognition. Additionally, an intelligent fire warning system based on the aerogel was designed, enabling sensitive and repeatable monitoring and alarm for high-temperature fire sources. The aerogel's high elasticity, thermal stability, and TE performance make it suitable for various applications, including self-powered high-temperature monitoring, industrial overheat warning, waste heat energy recycling, and wearable healthcare. The study highlights the potential of PEDOT:PSS/SWCNT composite aerogels in high-temperature environments and their promising applications in wearable electronics and fire warning systems.A highly elastic, flame-retardant, and high-temperature-resistant thermoelectric (TE) aerogel composed of PEDOT:PSS/SWCNT composites was fabricated, demonstrating excellent TE performance and mechanical properties. The aerogel exhibits a high Seebeck coefficient of 38.9 μV/K and low thermal conductivity of 0.074 W/m·K. When compressed, the aerogel shows enhanced TE performance, with a maximum power factor of 0.58 μW/m·K at 80% strain. A flexible TE generator made of 25 connected aerogels can generate a maximum output power of 400 μW at a temperature difference of 300 K, showcasing its high-temperature heat harvesting capability. The aerogel-based sensor can detect a wide range of temperatures (25–325°C) and recognize complex hand motions. A self-powered wearable sensing glove was developed for wide-range temperature detection and hand gesture recognition. Additionally, an intelligent fire warning system based on the aerogel was designed, enabling sensitive and repeatable monitoring and alarm for high-temperature fire sources. The aerogel's high elasticity, thermal stability, and TE performance make it suitable for various applications, including self-powered high-temperature monitoring, industrial overheat warning, waste heat energy recycling, and wearable healthcare. The study highlights the potential of PEDOT:PSS/SWCNT composite aerogels in high-temperature environments and their promising applications in wearable electronics and fire warning systems.