The invention relates to an ultra high-speed optical analog-to-digital conversion device. The ultra high-speed optical analog-to-digital conversion device comprises a high-speed pulse laser, a frequency spectrum broadening module, a repetition frequency multiplication module, an ultra wide band signal sampling module, a wavelength multi-channelizing module, parallel photoelectric conversion modules, parallel electric quantization modules and parallel data processing modules, wherein the high-speed pulse laser, the frequency spectrum broadening module, the repetition frequency multiplication module, the ultra wide band signal sampling module, the wavelength multi-channelizing module, the parallel photoelectric conversion modules, the parallel electric quantization modules and the parallel data tprocessing modules are sequentially connected. According to the ultra high-speed optical analog-to-digital conversion device, the high-speed pulse laser and the wavelength-division multiplexing technology are combined, while the advantages that the wavelength-division multiplexing technology is simple and practicable are kept, the defect that the output frequency spectrum of an active mode-locking fiber laser is narrow is overcome through the frequency spectrum broadening technology, high-speed photoelectric sampling is carried out through a broadband 1*2 electro-optical modulator, and by increasing the number of wavelength-division multiplexing channels or the number of parallel channels of the system, the bandwidth of a photoelectric detector and the sampling rate of an electric analog-to-digital converter are not increased while the sampling rate of the system is improved.