Within the framework of the dielectric continuum approximation, the confined longitudinal-optical (LO) and interface optical (IO) phonon modes in an n-layer coupling quantum well system are deduced and discussed. To describe the vibrating of the LO phonons, a proper eigenfunction for LO phonon modes is adopted. To deal with the IO phonon modes, determinant methods are employed. The quantized LO and IO phonon fields as well as their corresponding electron-phonon interaction Hamiltonians are also derived. This work can be regarded as a generalization of some previous works, and it provides a uniform method to solve the phonon effects on the multi-layer coupling quantum well systems.