To date, MXene has been discovered for its viability as alternatives to conventional saturable absorber such as carbon nanotube and graphene. The characteristics of high nonlinear saturable absorption, astounding modulation depth, flexible bandgap tunability, and high electron density near Fermi level are the fundamentals of the MXene as an excellent saturable absorber candidate. In particular, the research effort contributed to MXene in nonlinear ul-trafast optics are extensively growing because MXene comprises one of the largest families in 2D nanomaterials that provides huge combination possibilities by forming a class of metal carbide or metal nitride with 2D layered structure. Herein, this review summarizes the recent development on synthesis and material characterization of the MXene, the studies on its nonlinear saturable absorption and the application of the MXene saturable absorber in near-infrared mode-locked fiber laser. Finally, some issues and challenges as well as future perspectives of this novel material are discussed.