As a new type of energy harvesting device, the triboelectric nanogenerator (TENG) can convert almost all kinds of mechanical energy into electricity based on the coupling of triboelectrification and electrostatic induction. Here, a novel TENG is constructed with a conducting polymer polypyrrole nanowire (PPy NW) electrode, which is prepared by an electrochemical polymerization method with anodic aluminum oxide (AAO) as the template. The PPy NW-based TENG shows high output performance with a maximum short circuit current density of 23.4 mA m⁻² and output voltage of 351 V, which can light 372 commercial red LEDs. Moreover, a self-powered anticorrosion system powered by the PPy NW-based TENG is designed, which can provide extra electrons to inject into the surface of the protected metals, forming effective impressed current cathodic protection by harvesting mechanical energy or wind energy. This smart device has potential applications for protecting metals from corrosion in daily life, industrial production and ocean exploration by harvesting the energies in the ambient environment.