PMPS-PBzMA copolymer is prepared using PMPS/BzMA with different mass ratios,the methods of controlling film thickness by spin-coating and the best heat treatment temperature are studied. Near-infrared spectroscopy confirm that the material′s absorption is low in the 1310 nm and 1550 nm communications windows. Experiments show that the photobleaching effect of PMPS-PBzMA is mainly due to the Si-Si photo-oxidation,and accompanies by a slight refractive index anisotropy. Reduction of refractive index in saturation process is due to the Si-phenyl-light decomposition,and this process will alleviate the anisotropy. Experiments summarize in the relationship among the initial refractive index,the saturation refractive index and the PMPS/BzMA mass ratio,and find out that the initial refractive index of material prepared using W(PMPS):W(BzMA)=10% and the saturation refractive index of material prepared using W(PMPS):W(BzMA)=100% are approximate. According to these features,using initial refractive index of W(PMPS):W(BzMA)=10% material and saturation refractive index of W(PMPS):W(BzMA)=100% material and photobleaching techniques,multi-mode embedded waveguides are successfully fabricated,the propagation loss in a channel waveguide is 0.91 dB/cm at a wavelength of 1310 nm.