Enclosed liquid-solid triboelectric nanogenerators (LS-TENGs) have gained widespread attention due to the advantages of self-storage of liquid and less susceptibility to contamination, but are limited by the low output power density. Here, a tubular bulk effect electricity nanogenerator (TBE-ENG) is reported by inserting an internal electrode with an appropriate depth between the fluorinated ethylene propylene (FEP) film and the glass cross- in the tube. The TBE-ENG can achieve an output current of 5.0 mA and a peak power density of 2169 W m−3 after adding a 1 M sodium chloride solution, which are much higher than those of the enclosed LS-TENGs in previous studies. The mechanism of TBE-ENG is elucidated via an equivalent capacitor model, and the effects of the electrode spatial position, dielectric layer thickness, and liquid properties on the output performance are well revealed in combination with experiments. Moreover, the applicability of TBE-ENG and its application for driving electronic devices are demonstrated. This work lays the groundwork for the design of higher-performance enclosed LS-TENGs, and greatly expands the application of the bulk effect.