A kind of polymer/SiO2 hybrid Mach-Zehnder interferometer (MZI) variable optical attenuator (VOA) is designed and fabricated. The VOA has lower power consumption than the VOA based on inorganic materials and faster response than the polymer VOA. The cross section size of the single mode waveguide is designed and optimized according to the single mode transmission conditions of ridge waveguide, and the structure of device is also simulated. The VOA with low power consumption and fast response is obtained by using the photolithography and wet-etching fabrication processes. With 1550 nm optical communication wavelength, the dynamic attenuation range of the fabricated VOA is 23 dB and the maximum power consumption is 14 mW. The rise and fall times of the device are 252 μs and 384 μs. The experimental results show that the VOA has a lower power consumption and a faster response with using the organic/inorganic hybrid structure and optimizing the device structure.