A kind of novel organic-inorganic hybrid core layer material with good optical properties and high thermal stabilities was synthesized via sol-gel process. Epoxy-crosslinking can be realized in the hybrid material owing to the existence of organic flexible lateral chains in the molecules. Compared with the inorganic SiO2-TiO2 system, this kind of material exhibited high thermal-optic coefficient(10-4/K) and excellent film characteristics. A kind of thermal curable resist P(MMA-GMA) was synthesized as the cladding material. The embedded waveguide thermo-optic switch of Mach-Zehnder type was designed and fabricated well. The insertion loss of the device is 10 dB, the driving power is 15 mW, the switching time is less than 1 ms and the extinction ratio is 15 dB.