Purpose <p>Vibration and noise not only affect human health, but also cause damage to machinery and equipment. In this paper, a single-phase ultra-wide band gap metamaterial integrating negative refraction and tunable band gap was proposed to enhance vibration control and noise reduction.</p> Methods <p>A composite star-chiral structure (SCS) was designed, and finite element analysis (FEA) was employed to simulate its band structure. multi-objective optimization algorithms were subsequently employed to fine-tune the geometric parameters, enabling adjustable band gap performance across target frequency ranges.</p> Results and Conclusion <p>The SCS achieved a total band gap coverage of 69.55% across 5500 Hz. Through multi-objective optimization and derived design, the band gap onset frequency of 615.50–850.25 Hz, the widest band gap of 2173.70–3440.61 Hz, and the total band gap coverage of 69.37%-77.77% were achieved as adjustable. Notably, the structure demonstrates dual functionality: negative refraction and ultra-wide band gap. The research provided a new strategy for applications in aerospace, automotive engineering, and smart infrastructure.</p>