With the increasing global demand for clean and renewable energy, liquid–solid triboelectric nanogenerators (LS-TENGs) have emerged as promising candidates for efficient high-entropy energy harvesting. However, their practical application in directly powering electrical devices is limited by high impedance, low current, and alternating output characteristics of LS-TENGs. To address these limitations, we propose a novel energy management liquid–solid triboelectric nanogenerator (EMLS-TENG) employing an external energy storage capacitor and a mechanical switch to construct an energy regulation mechanism, enabling high-amplitude pulsed direct current output and ultra-low impedance. Compared to conventional LS-TENGs, the EMLS-TENG achieves a 7500-fold increase in output current and a 79-fold increase in output power. The effects of key parameters, including the selection of triboelectric materials, electronic components, switch distance, and switch size on the output performance of the EMLS-TENG was systematically investigated. Through an integrated design, the EMLS-TENG achieves a record-setting power density of 1135 W/m3 at the impedance of 0.5 MΩ and a current density of 1120 mA/m2. Furthermore, the EMLS-TENG successfully powered six commercial 15 W light tubes and supplied energy to various commercial sensors. This work provides a leap forward in improving the performance of LS-TENGs and accelerating their commercial implementation.