A method for preparing a microstructure on the surface of glass by titanium oxide nanoparticle-assisted infrared nanosecond laser, including the following steps: (1) dropwise applying a titanium oxide nanoparticle hydrogel onto the surface of a glass sample; (2) pressing another piece of glass on the surface of the hydrogel, so the hydrogel is evenly distributed between the two pieces of glass, and allowing the two pieces of glass to stand horizontally for a period of time to air-dry the hydrogel; (3) separating the two pieces of glass to obtain a glass with a uniform titanium oxide nanoparticle coating; (4) forming a microstructure using an infrared nanosecond laser with a wavelength of 1064 nm; and (5) performing after-treatment, including ultrasonically cleaning the sample with acetone, absolute ethanol and deionized water respectively for 10 min to remove titanium oxide nanoparticles attached to the surface, to obtain a glass sample with the microstructure.