The invention provides a high-peak-power picosecond and nanosecond short-wavelength fiber laser. A high-speed pulse modulation circuit board modulates a narrow-linewidth semiconductor laser seed source to generate a narrow pulse signal of 200 ps to 1 ns. A narrow-linewidth pulse small signal is amplified by two polarization-maintaining fiber pre-amplifying stages and the two-time narrow-band filtering. In a power amplification stage, a reverse pumping source and a high-doped fiber are used to realize power amplification to obtain high-power 1[mi]um fundamental-frequency signal light. Because the fundamental-frequency spectrum has a high side-mode suppression ratio, a narrow line width, and high peak power, the laser of the invention has high frequency multiplication conversion efficiency,and the pulse width and the pulse frequency are arbitrarily adjustable in a large range. Further, the laser is low in cost and has a wide application prospect in the field of industrial micromachining.