The inversion-symmetry breaking Rabi model under ultra-strong coupling condition is studied with the adiabatic approximation method. The analytical expressions of the eigenfunctions and the eigenvalues are obtained, and the influence of the inversion-symmetry breaking on them is also studied. The dynamical behavior of the system, with initial status of Fock state and coherent state for the quantum harmonic oscillator, is discussed. The collapse and revival phenomena have been put particular attentions. The results show that the inversion-symmetry breaking changes the time and height of collapse and revival.