Constructing micro/nanostructures based on TiO2 has attracted increasing attention due to the excellent properties of TiO2. In this study, we report a simple method to directly fabricate TiO2 micro-devices, including Fresnel lens, gear structures and suspended beams only by laser direct writing and selective-etching processing. This route shows great potential in fabricating TiO2 structures for micro-electro-mechanical systems, diffractive optical elements and bio-applications, owing to its maskless process, low cost, and flexible dry/wet alternative etching treatment.