Microbial fouling and the resulting corrosion in marine environment cause severe economic and safety problems. It is urgent to develop feasible and efficient methods for controlling marine microbial fouling. In this study, the self-powered antifouling ultraviolet C (UVC) pipeline sterilizer was developed based on modified freestanding rotary triboelectric nanogenerator (MFR-TENG) with the function of discharge stimuli. Taking the advantage of breakdown discharge stimuli, the output voltage of the MFR-TENG is up to 6.9 kV, which is about 3-fold higher than the case in the absence of discharge stimuli (2.4 kV). This MFR-TENG provides sufficient energy for mercury vapor to generate ultraviolet radiation. The sterilization experiments demonstrate the self-powered antifouling UVC pipeline sterilizer exhibits superior antimicrobial ability against typical corrosive bacteria, including Hal omonas titanicae, Pseudomonas aeruginosa, and miscellaneous bacteria cultured in raw seawater. Further inves tigation on morphological change of bacterium demonstrates the UVC radiation excited by discharge stimuli cause significant damage to the bacterial membrane. As a result, the antibacterial rate of the self-powered antifouling UVC pipeline sterilizer (75%) is higher as compared with that without discharge phenomenon (44%) after 10 min of sterilization. This study offers an eco-friendly and efficient strategy for preventing marine microbial fouling.