Triboelectric nanogenerators (TENGs) have been introduced as a new cost‐effective technology for harvesting renewable wave energy for their unmatchable performance in low frequency (<5 Hz). Here, bifilar‐pendulum‐assisted multilayer‐structured triboelectric nanogenerator (BM‐TENG) modules incorporated into a vessel for wave energy harvesting are reported, which have a high output performance and adaptive capacity in actual marine environment. Compared with previous research work on wave energy collection by TENG, the designed BM‐TENG, which is optimized by the structure and material, presents a milestone power density of 200 W m−3 and this performance is an improvement of 1–2 orders of magnitude. More importantly, by using a vessel as a platform, TENG can be integrated into it to eliminate the impact of the marine environment and enable convenient maintenance, easy connection, and long‐term stable operation of TENG. The findings provide not only a new design methodology for TENG but also a feasible method to harvest renewable energy efficiently.