Purpose <p>The single-oscillator locally resonant phononic crystals (SOLRPCs) exhibits the shortcomings of excessively narrow bandgap coverage and unsatisfactory elastic wave blocking effect. In this regard, this study constructs multiple-oscillator locally resonant phononic crystals (MOLRPCs) based on the design concept of multiple oscillators in series with each other, which induces more local resonance modes and efficiently broadens the overall characteristics of the bandgap by utilizing the multiple coupling effect among oscillators.</p> Design Method <p>The bandgap characteristics are calculated based on the finite element method and the bandgap formation mechanism is analyzed by vibration mode and vibration energy. The frequency response function is exploited to investigate the transmission behavior of elastic wave within the structure of finite-period MOLRPCs. Bandgap parameter analysis is carried out and the mechanism of damping effect on the transmission behavior is explored. A mass-spring equivalent model is developed to theoretically determine the bandgap range.</p> Findings <p>The multiple coupling effect between oscillators can induce more local resonance modes in MOLRPCs and effectively enhance the bandgap characteristics. The low-frequency elastic waves located within the bandgap coverage are significantly hindered and suppressed during propagation. The damping effect of the coating can effectively suppress the resonant excitation behavior during elastic waves transmission, while the damping effect of the matrix has no effect on the elastic waves transmission behavior. The mass-spring equivalent model possesses good accuracy and can quickly determine the bandgap range of MOLRPCs theoretically.</p> Practical Implications <p>This work can provide a theoretical reference for the multi-perspective optimal design of bandgaps in locally resonant composites or structures.</p>