<p>This paper proposes a new type of composite acoustic metamaterial to address the issue of low-frequency vibrations below 0–100&#xa0;Hz generated by rotating mechanical equipment in orbit, which are transmitted to important units and affect their performance. The material is attached to the transmission path area between mechanical equipment connections to achieve low-frequency vibration reduction. The new type of composite acoustic metamaterial is composed of quadrilateral and star-shaped structures. Based on Bloch’s theorem, band analysis is conducted on the three structures, and the bandgap width of the three structures is discussed to obtain the optimal structure. In addition, analyze the mechanism of bandgap generation in new composite acoustic metamaterials and discuss the influence of geometric parameters on bandgap. Finally, the propagation characteristics of elastic waves in the structure were analyzed using three-dimensional dispersion surfaces and phase velocities. The frequency response function of elastic waves propagating in the structure was calculated, and the corresponding relationship between vibration propagation and bandgap frequency range of finite period structures was studied based on finite element method. This verified that the structure can effectively suppress vibration propagation in the transmission path region. Therefore, the design method of composite acoustic metamaterials can effectively achieve the attenuation of elastic waves, providing a new design idea for the vibration and noise reduction design of acoustic metamaterials.</p>