Digital Array Radar (DAR) is a fully digitized phased array radar in which digital beam forming technique is used both in receiving and transmitting. Firstly, this paper introduced the typical ar-chitecture of DAR. Then, it analyzed the characteristics of DAR, such as the low demand of dynamic range, the ultra low side-lobe, the low probability of Intercept and the broad field of regard. Finally, it discussed the technology problems in the process of engineering realization, including the digital TR Module production, the broadband realization, the ultra low side-lobe and the channel consistency technique. It will be helpful for the fully development of DAR.