Switching-mode energy management strategies (EMSs) play a pivotal role in promoting the utilization of triboelectric energy, but their implementation is predominantly through the simple series connection of a synchronous switching unit with a full-wave rectifier, which leads to overmany electronic components and hence overmuch energy dissipation. To address this issue, we propose herein a self-powered single-transistor synchronous switching strategy (SPST-3S) for triboelectric nanogenerators (TENGs), whose implementation depends only on a half-wave rectifier and a single NPN transistor, requiring the minimum number of electronic components for switching-mode EMSs so far. Through the rational combination of a transistor with a half-wave rectifier, the SPST-3S enables both real-time detection of the TENG voltage peak and automatic switching actions, achieving high energy conversion efficiency of 88.6%. Theoretical analysis and experimental tests demonstrate that, with the SPST-3S, the optimal output impedance of a rotary TENG (R-TENG) is reduced by 99.97% (from 650 MΩ to 0.19 MΩ) and the peak output current is increased by a factor of 44 (from 3.5 μA to 154 μA). In addition, sustaining the continuous operation of a hygrothermograph, which cannot be realized by the energy management circuit (EMC) based on the full-wave rectifier, is achieved by the EMC designed with the SPST-3S. This study introduces a distinctive and integrated EMS for TENGs, offering a promising technical route for achieving efficient utilization of triboelectric energy and thus advancing TENG’s application in various fields.