Abstract: Digital array radar has large channels and large amount of equipment. The miniaturization and programmable characteristics of digital transceiver unit are used to reduce the complexity of the receiving array, improve the reliability and reduce the cost. With the rapid development of digital logic integrated circuits, AD sampling rate and the output frequency of direct digital frequency synthesizer(DDS) are improved, conversions between analog signal and digital signal are close to the antenna as far as possible, which means the digital array radar will realize full-digitization. This paper analyzes the application of multi-channel analog-to-digital conversion, DDS and synchronization in digital array radar, through integrated and efficient design, principal analysis of digital transceiver unit and intensive design of the circuit are realized, the main design points and control parameters in the system design are briefly described.