The needs of modern wideband digital receivers for high performance analog-to-digital converters (ADCs) are increasing gradually, but the electronic ADCs cannot realize UWB direct digital sampling due to carrier migration rate limit. Based on the characteristics of ultra-wideband and ultra-high speed of photonic technology, an ADC technology with optoelectronic hybrid structure was proposed in this paper. Optical sampling based on ultrashort optical pulse was used to replace the sample/hold (S/H) circuit used in electronic semiconductor technology to greatly improve the sampling bandwidth, and time division multiplexing and multichannel ADC quantization technology were used to realize digital coding. Finally, the system performance was improved by digital domain equalization and linearization. The direct sampling of microwave signals with frequency greater than 24 GHz, and the sampling signal-to-noise ratio greater than 40 dB were realized, which provided an effective way for UWB microwave signals to be directly digitized with high precision.