A high power 1030 nm passively mode-locked ytterbium-doped picosecond fiber laser by master oscillator power amplifier (MOPA) in all-fiber configuration is demonstrated. The laser system consists of the picosecond seed and three stages of ytterbium-doped all-fiber amplifiers. The seed is mode-locked by semiconductor saturable absorber mirror (SESAM). And a stable output is obtained with 30.7 ps pulse width, 29.0 MHz repetition rate, and 30 mW average output power. The laser operates at 1030.4 nm with a spectral width of 0.15 nm. After three stages of fiber amplification, the final output power is scaled up to 101 W in a 30 μm/250 μm double cladding ytterbium-doped fiber with the slope efficiency of 76.7%. The laser performance with the pulse width of 36.6 ps, pulse energy of 3.48 μJ, peak power as high as 97 kW operating at 1030.4 nm with bandwidth of 1.46 nm is achieved, and the beam quality M2 is 2.78.