A simiplified method is presented for analyzing the optical characteristics of the mode in the aaymmtric five-layer MOS optical waveguied with finite thicknesses of the metal cladding and the oxide buffer layer. The approximate formulas are derived for calculating the propagating constant and the absorption loss coefficient of the TE mode. Compared with the calculated results, the accuracy of this method is determined. In order to realize the single-mode propagation in the waveguide with low absorption loss coefficient of the TE mode. Compared with the calculated results, the accuracy of this method is determined. In order to realize the single-mode propagation in the waveguide with low absorption loss the selections of some guided parameters are discussed.