The effective and efficient refractive index of a multilayer optical waveguide is computed by taking into account the various order modes of the waveguide, such as the Quasi-Transverse Electric/Transverse Magnetic (Quasi-TE/TM) mode. According to the effective refractive index method, the effective refractive index of the Quasi-TE/TM mode is calculated from the electromagnetic field curve distribution calculated for each mode in the 6-layer loss optical waveguide compute the effective refractive index each order of TE/TM mdes. Further, we analyze the dependence of the waveguide properties on the structure. We conclude that the mode effective refractive index and mode order do not decrease monotonicallythe lossy waveguide mode is more prevalent. The research work in this paper can be used as the theoretical basis for the design, fabrication and application of practical optical waveguide devices.