This article investigatedthe acoustic vibration coupling response of a fully elastic cavity structure controlled by piezoelectric shunt technology under an internal sound source excitation.Based on the acoustic vibration equation, this article analyzed the dominant factors of the acoustic vibration response of the fully elastic cavity structure, revealed the coupling mechanism between the different panels and the acoustic cavity. In fully elastic cavity vibration, the coupling between the panel mode and the acoustic cavity mode can be calculated using orthogonal integration, and there exists a corresponding dominant panel for a specific resonance frequency. Piezoelectric shunt regulation based on dominant panel strategy can maximize control effectiveness. A vibration and noise control system for an elastic cavity based on a piezoelectric shunt circuit was established. By controlling the vibration in the dominant frequency range corresponding to the panels of the elastic cavity, multiple resonance peaks were suppressed in the overall response of the elastic cavity system. The vibration response of the wall panels at the first two resonant frequencies, 88 Hz and 144 Hz, decreased by 17 dB and 9 dB respectively, while the peak sound pressure inside the cavity reduced by 17 dB and 7 dB, and the peak radiated sound pressure outside the cavity decreased by 13 dB and 4 dB.