We have proposed and implemented a 2.8 μm synchronously mode-locked pulsed fiber laser pumped by a 976 nm single-mode pulsed laser. The 2.8 μm pulsed laser repetition rate is 6.534 MHz, the center wavelength is 2784.7 nm, the 3 dB spectral width is 0.4 nm, and the maximum output power is 15 mW. Due to the low output power, it is difficult to detect the actual pulse duration through the autocorrelator, but the oscilloscope shows 3.1 ns, which is close to the detection limit pulse width of the photodetector. Next, we will further optimize and improve the quality of the 976 nm pump light, use a fluoride fiber with a thinner core to improve the effect of cross-phase modulation, and select an active fiber with a relatively high doping concentration to increase the output power and achieve ultra-short mid-infrared mode-locked pulse. In short, based on the synchronous pump mode locking technology, there is no need to introduce any active and passive modulation devices in the resonator, and the system has a simple structure, good stability, and easy to achieve entirely monolithic fiber lasers. It provides a solution for realizing stable and reliable mode-locked pulse lasers in the mid-infrared regime.