A laser micro/nano processing system (100, 200, 300, 400) comprises: a laser light source used to provide a first laser beam having a first wavelength and a second laser beam having a second wavelength different from the first wavelength, with the pulse width of the first laser beam being in the range from a nanosecond to a femtosecond; an optical focusing assembly used to focus the first laser beam and the second laser beam to the same focal point; and a micro mobile platform (21) controlled by a computer. Also disclosed are a method for micro/nano-processing photosensitive materials with a laser and a method for fabricating a device with a micro/nano structure using laser two-photon direct writing technology. In the system and methods, spatial and temporal overlapping of two laser beams is utilized, so as to obtain a micro/nano structure with a processing resolution higher than that of a single laser beam, using an average power lower than that of a single laser beam.
