To develop environmentally friendly and durable marine antifouling coatings, a double-layer composite coating integrating piezoelectric antibacterial and superhydrophobic antifouling properties was designed. The piezoelectric layer (EPBT) was fabricated by dispersing ferroelectric barium titanate into epoxy resin, while the superhydrophobic layer (SiPU) was constructed by PDMS-modified polyurethane with micro-nano structures. The coating exhibited a water contact angle of 153.3 degrees, a sliding angle of 4.6 degrees, and a low surface energy of 22.4 mN/m, even after 2000 cm abrasion tests. The maximum piezoelectric output reached 9 V under mechanical stimulation. The reactive oxygen species (ROS) generated by the piezoelectric effect endowed the EPBT30/SiPU coating with a 98 % inhibition rate against E. coli and S. aureus. The coating also reduced algal adhesion by 86.8 % for P. tricornutum and 73.7 % for N. closterium. A 30-day marine field test validated its antifouling performance due to the synergistic combination of superhydrophobicity and piezoelectricity. These results demonstrate the coating's potential as an eco-friendly and high-performance solution for marine antifouling applications.