Abstract: The principle, key technology and implementation of a high-performance multi-channel excitation source system is introduced in this paper. The factors influencing the phase stability of the excitation signal, the means of implementation and the test method are mainly discussed. The implementation of transmitter digital beamforming, low spurious and low phase noise are analyzed. This system is mainly composed of waveform generation and excitation channels. It has the characteristics of arbitrary waveform generation, high amplitude-phase consistency and stability, and easy channel number expansion. It is especially suitable for digital array radar with small or medium-scale channel number. First, the main parameters of the excitation source system are presented, and the principles of transmitting digital beamforming and multi-channel excitation source system are explained. Then, the design scheme of the system is given, and the key technologies such as clock and timing transmission management, signal phase stability, transmitting digital beamforming, low spurious and low phase noise are analyzed. Finally, the test methods and results of the main parameters are given.