In order to realize supercontinuum (SC) generation with broadband spectral range covering more visible wavelength, a pump wavelength tunable all-fiber SC fiber laser was experimentally investigated. A tunable nonlinear polarization rotation mode-locked fiber laser was proposed, which could output picosecond dissipative solitons pulse with nine different central wavelengths from 1 041 to 1 076 nm. After two-stage power amplifier, the tunable laser with relatively high power was coupled into 10 m long photonic crystal fiber, SC with nine different output spectra was realized when the pump laser power was 500 mW. And it was found that when the pump laser central wavelength was 1 050 nm, the generated SC was with broad and flat spectrum and containing a large part of visible wavelength components. To further broaden the SC spectral range and obtain better flatness, the pump laser power was enhanced up to 1.45 W, the generated SC output power was 600 mW, while the short-wavelength boundary was 470 nm, 10 dB spectral bandwidth was 1 053 nm within 600—1 700 nm wavelength range.