The past decade has seen great progress of mid-infrared mode-locked fluoride fiber lasers, enabling a range of new applications. Different mechanisms, e.g., MSA, NPR, and FSF, have been introduced into rare-earth ions doped fluoride fiber lasers to demonstrate mode-locked operations in the spectral region of 2.73.6 μm and with the time scale of 10 s of fs to ps. However, most of these systems involve some local free-space alignments, weakening the stability, reliability and compactness while preventing pulse narrowing and soliton formation especially at the strong water vapor absorption band. Thus the development towards a robust all-fiber structure is undoubtedly the trend in the future. In addition, the performance parameters of the mode-locked fiber lasers in the mid-infrared fall far short of that in the near-infrared, which needs to be improved by employing new mode-locking techniques and designs. Parallel to the mid-infrared continuous wave fluoride fiber lasers, further extending the wavelength of mode-locked pulses is also an important direction.