In the past decade, mid-infrared ultrafast mode-locked lasers have made significant progress, effectively promoting their applications in many fields, including mid-infrared frequency combs, molecular spectroscopy, material processing, laser surgery, molecular organism, and chemistry. Herein, starting with the progress of mid-infrared ultrafast fiber lasers in recent years, we introduced the development of various optical fiber lasers in this band and discussed femtosecond fiber laser solutions achieving shorter pulse widths and farther wavelengths. Further, we introduced chirped pulse amplification and nonlinear amplification. Thus, mid-infrared ultrafast fiber lasers are in the high-speed development stage and will have abundant applications in the future.