We present a high-power white supercontinuum (SC) all-fiber laser source with average power of 67.9 W, spectrum ranging from 500 to 1700 nm, and spectral width exceeding 1000 nm for spectrum with flatness below 10 dB (except pump wavelength). Also, the visible waveband power (below 850 nm) occupies about 21% of the total SC power. A 145 W high-power picosecond pulse fiber laser is specially designed with high repetition frequency of 656 MHz to reduce nonlinear effects. Meanwhile, a homemade high-power mode field adaptor that can operate stably at hundreds of watts of pulse power has high coupling efficiency of 82%. To our knowledge, the 67.9 W white SC fiber laser source we achieved is the highest reported with such a wide and flat optical spectrum.