We report a hybrid two-step approach for fabricating silica micro/nanofibers with different diameters (the minimum one down to 180 nm). Due to tapering and etching techniques introduced to this approach, the time is reduced from hundreds of minutes to several minutes to manufacture silica nanofibers by etching and the complexity of tapering mechanical system is brought down, because this approach has the ability to control the micro/nanofiber diameter on a nanometer-scale. Uniform nanofibers with losses as low as 0.05 dB/mm at 1.55 μm wavelength are obtained suggesting the advantage of the hybrid approach to build up micro/nanofiber-based devices, especially in locally changing the structure of micro/nanofiber.