A system for detecting single-shot pulse contrast includes a correlator generating a correlation signal, a spectral filter filtering light signals having wavelengths different from the correlation signal, a fiber array comprising a plurality of fibers with different lengths for transmitting the correlation signal in parallel forming parallel correlation signals, and a fiber bundle bounding the fibers at the end thereof for converging the parallel correlation signals, wherein due to different lengths of the fibers, the parallel correlation signals are converted into serial correlation signals at end of the fibers, a plurality of fiber attenuators spliced into at least one of the fibers respectively for attenuating the parallel correlation signals, a detector for detecting the serial correlation signals to produce analog signals, an A/D convertor converting the analog signals to digital signals, and a computer for processing the digital signals for retrieving the single-shot pulse contrast.