It is hard to fabricate parts of Micro/Nano-Electro-Mechanical Systems (MEMS/NEMS). To solve this problem, the method of two-photon photopolymerization of femtosecond laser which had subdiffraction-limited spatial resolution was researched. Micro/nano fabrication system of Ti-sapphire femtosecond laser was set up. Process experiments of femtosecond laser two-photon photopolymerization were carried out using the material of liquid polymer. The experimental results indicate that the size of single solidification point reduces and the fabrication resolution improves with the reduction of laser power. The surface roughness value of the fabricated parts decreases, and the fabrication efficiency reduces with the scanning step reducing. 3D micro/nano structures composed of micro walls and nano wires was designed with CAD software and fabricated with two-photon photopolymerization of femtosecond laser. Nano wire whose diameter was smaller than 100 nm was fabricated after optimizing the process parameters. It is verified that two-photon photopolymerization of femtosecond laser provides an efficient method for micro/nano device.