Wearable sweat sensors can detect and monitor various substances in sweat, providing valuable information for healthcare monitoring and clinical diagnostics. Recent advances in flexible electronic technologies have enabled the development of wearable sweat sensors that can measure sweat rate and biochemical substances in real time, although several challenges remain, such as power management and sweat extraction issues. Here, a passive sweat extraction strategy as well as a self-powered monitoring system (SEMS) is reported to be designed for sedentary individuals, i.e., elders. The SEMS system comprises a wearable triboelectric nanogenerator (TENG) for sweat extraction, a sweat-activated battery (SAB) as the integrated power source, carbachol-loaded iontophoresis electrodes for sweat extraction, microfluidics with biosensors for detecting physiological information in sweat, and near field communication (NFC)-based wireless microelectronics for data communication, processing, and collection. By tapping the TENG, sedentary people can passively extract sweat based on the iontophoresis process, allowing the sensors to detect biological information in sweat. The good flexibility of the SEMS device enables real-time and non-invasive detection of sweat analytes in a wearable format. This system offers a new strategy of sweat collection and analysis for the elderly group, and therefore can help to understand human physiology and personalize health monitoring deeply.