A broadband optical parametric chirped-pulse amplifier applicable to the technical field of lasers. The amplifier comprises a narrow-band picosecond laser (70), a pulse laser stretcher (10), an optical coupling mirror (20), a beam expansion / contraction system (30), a periodically poled crystal (40), a spectroscope (50), and a pulse laser compressor (60), wherein the periodically poled crystal (40), which has a periodical domain inversion structure, is used for separating generated idler light from a chirped-pulse laser / pump light so as to suppress energy backflow after the broadband optical parametric chirped-pulse amplifier enters the stage of saturated amplification; and thus, the broad optical parametric chirped-pulse amplification of a broadband is realized. The broadband optical parametric chirped-pulse amplifier not only suppresses the backflow of signal light energy, but also has a very broad gain bandwidth as a result of the simultaneous optimization between pulse energy (conversion efficiency) and pulse width (gain bandwidth), such that the outputtable peak power of the broadband optical parametric chirped-pulse amplifier is greatly increased, and the performance of the optical parametric chirped-pulse amplifier is improved.