Polydimethylsiloxane is a kind of silicone which has merits of cost effective, good dielectric properties, and lower optical transmission loss in infrared range. Since the Poly［(methyl methacrylate)-co-(Disperse Red 1 methacrylate)］ is applied as the active layer, in order to avoid the passive influence between the core and claddings, polydimethylsiloxane was chosen to be the cladding layer. An inverted ridge polymer waveguide Mach-Zehnder Electro-Optic modulator was designed and fabricated. Aiming at the deposition phenomena which arises when only using SF6 in polydimethylsiloxane reactive ion etching, a method of utilizing the mixture of SF6 and O2 was proposed for polydimethylsiloxane reactive ion etching process. It was found that when the flux ratio of SF6∶O2 is 50 sccm∶10 sccm, the groove has the best shape. Through the optical test, the fabricated inverted ridge Mach-Zehnder waveguide has a good near-infrared light output. Co-planar waveguide electrodes based on Aluminum material were designed and fabricated, and signal response of electro-optic modulator was observed.