We demonstrate an all-fiber picosecond fiber laser in a master oscillator power amplifier configuration. The seed source is a soliton-type passively mode-locked Yb-doped fiber laser by a semiconductor saturable absorber mirror and chirped fiber Bragg grating. The pulse width of the seed laser is 4.5 ps with a repetition rate of 15 MHz. A highly doped active fiber with a large core diameter (50 μm) is employed to boost the average power of the seed pulses to 117 W with 11 ps pulse width and 709 kW peak power. The corresponding output beam quality factor at maximum output power is 3.7. The all-fiber construction of the whole laser system enables compact size and robust operation.