With the development of high speed ADC and general processor with high performance, the digitalization degree of radar has reached a level much higher than before. Firstly, this paper analyzed the advantages of Digital Array Radar (DAR). Secondly, it introduced several typical DAR systems and summarized the typical architecture of DAR. Finally it introduced the development of RF direct sampling all-digital receiver, all-digital quadrature demodulation, wideband channel equalization, and the wideband signal digital beamforming technology. With the development of relevant technology, the array radar will surely develop to be digital, software defined and multifunctional.