Monitoring the quality of perishable food in real time is critical for reducing the societal costs and foodborne diseases. A self-powered triboelectric nanogenerator (TENG)-based wireless gas sensor system (TWGSS) is presented to realize selective, sensitive, and real-time wireless food-quality assessment in a cold-supply chain. TWGSS can real-time monitor the key food spoilage markers gas (e.g., ammonia) and maintain excellent stability under high humidity (75%) and low temperature (−18 °C). Benefiting from the three-dimensional porous structure of wood and ammonia sensitive properties of the carbon nanotubes materials, output voltage of the TENG selectively decreases with the increase of ammonia concentrations from 50 to 500 ppm. Moreover, the TENG exhibits an ammonia-sensing response of 0.85 at 500 ppm ammonia, which is much higher than the other common gases released from perishable foods under the same gas concentrations. Through system integration and power management, a self-powered triboelectrically driven system that can also be used as a gas sensor and wirelessly transmit data to the user interfaces. This work provides a design concept for the application area of the TENGs to the assessment of food quality, and also promotes the development of self-powered systems in food industry. Display omitted ●A wood-based triboelectric nanogenerator (TENG) was developed and used as NH3 sensor.●The self-powered TWGSS was proposed by integrating the TENG with the wireless circuitry.●The TWGSS realized real-time wireless food-quality assessment in a cold-supply chain.