Harvesting high entropy energy (HEE) from the environment is a promising route for powering various smart terminals. Although triboelectric nanogenerators (TENG) exhibit an infinitely bright future as an excellent energy conversion technology, continued efforts are needed for the efficient harvesting of HEE, especially in harsh environments. Here, we report a self-powered system composed of modular TENG (M-TENG) and power management circuit (PMC) that efficiently captures HEE in harsh environments, and provides a stable output of 126 s with only stored energy. With the assistance of an optimized gear train, weak HEE can produce greater torque to drive the escapement, while the escapement releases energy evenly to the TENG to produce a stable and continuous electrical output. The influence of a series of structural parameters on the output performance of the M-TENG has been systematically investigated and validated by finite element analysis (FEA). The maximum open-circuit voltage (VOC), short-circuit current (ISC), and transfer charges (QSC) can reach 500 V, 6 μA, and 125 nC, respectively. Moreover, the quantified stability and environmental adaptability of the M-TENG are validated. This work presents a paradigm for the efficient utilization of HEE in harsh environments and brings new inspiration for developing emergency self-rescue equipment.