The invention relates to an optical parametric oscillator, which comprises a nonlinear optical material (1) with the double-zero dispersion wavelength, a high reflector (2), an output mirror (3), a parametric oscillation optical beam collimator (4), a parametric optical line width compressor (5), a pumped optical coupler (6), a lambda/2 phase retarder (7), a laser power controller (8) and an optical isolator (9). The nonlinear optical material (1) has a double-zero dispersion wavelength and is arranged in a resonant cavity formed by the high reflector and the output mirror. The pumped opticalwavelength is in the anomalous dispersion regime of the photonic crystal fiber, thereby ensuring the phase matching conditions and generating the highly efficient four-wave mixing effect. For the parametric oscillation formed by simplifying the four-wave mixing, the wavelengths of the two parametric lights are respectively arranged at the double-zero dispersion wavelength of the photonic crystal optical fiber, thereby realizing the group velocity dispersion compensation of the parametric light, solving the problem of the ultra-short pulse dispersion compensation, and greatly reducing the pumping threshold.