Ultrafast lasers refer to lasers with very narrow widths. Ultrafast laser has extremely high instantaneous power, and its interaction with matter presents a non-linear, nonequilibrium and multi-scale state. With the unique characteristics of ultrafast(short pulse duration), ultrahigh (high instantaneous power) and ultrafine (fine processing structure), the realized nonlinear laser manufacturing technology can break the limitations of traditional micro-nano manufacturing and realize the ultrafine processing of various difficult-to-machine materials and complex micronano structures. It demonstrates unique application value in frontier fields such as microoptics, biomedicine, and intelligent electronic devices with precision ranging from sub-micron to nanoscale. The frontiers of femtosecond laser micro/nano machining technology was focused on. Firstly, the processing characteristics of femtosecond laser technology and the main processing methods were introduced, including femtosecond laser direct writing and femtosecond laser parallel processing. Then, the frontier application fields of femtosecond laser processing technology were discussed, such as micro-nano optical devices, microfluidic devices, multifunctional structured surfaces and biomedical engineering. Finally, the future development trend and research direction of femtosecond laser processing technology were prospected.