Purpose <p>Acoustic metamaterials composed of artificially designed microstructural units can flexibly and accurately control sound waves, solve the problems of broadband and low-frequency noise reduction and sound insulation, and have important application value. However, most existing acoustic metamaterials suffer from structural complexity and large volume.</p> Methods <p>In this paper, a simple dual-band negative mass density acoustic metamaterial with U-shaped tube embedded with perforated diaphragm is proposed. By combining the standing wave resonance principle with coupling interaction, the accurate resonance frequency formula of U-shaped tube embedded with perforated diaphragm is derived. The research is conducted from both theoretical and simulation aspects, and experiments are designed to verify the transmission performance of the designed U-shaped tube.</p> Results <p>The results show that when the perforated diaphragm is located in a symmetrical position, there is only one resonant frequency; There are two resonant frequencies in asymmetric position, and the resonant frequencies increase with the increase of diaphragm opening size and decrease with the increase of diaphragm thickness.</p> Conclusion <p>Therefore, when the perforated diaphragm is in asymmetric position, the acoustic metamaterial embedded with perforated diaphragm in U-shaped tube can produce dual-band negative mass density characteristics, and realize dual-band high-performance transmission noise reduction. The theoretical formula of the derived resonant frequency is consistent with its simulation results, and the experimental results are also in line with the simulation. This kind of acoustic metamaterial has the advantages of high space utilization rate, programmed modeling, customized production, 3D quantitative printing, etc., and has broad application potential in the field of multi-frequency noise reduction and sound insulation.</p>