Within the framework of the effective mass approximation, a detailed investigation of the effects of an external (DC) electric field on the electronic and optical properties of a multi-layer cylindrical ZnS/ZnO quantum dot with fixed height and radius respectively at 10 nm and 5 nm, while modeling the ZnO wells using a parabolic potential. Numerical results were carried out using the Finite Difference Method (FDM), in order to compute the confinement energies, probability densities, expectation value for the potential describing a (DC) electric field for both the ground state and first excited state, and finishes by deducing the transition energy, transition dipole moment (TDM) and the absorption coefficient (AC) while taking into account multiple layer thickness configurations as we vary the electric field strength $F$. The results shows that varying the (DC) electric field strength does has an noticeable impact on the electronic and optical properties while all other inputs are kept unchanged.