Abstract: In order to rationally evaluate the performance of angle tracking, distance decoy and detection when detecting and tracking the dual stealth aircraft formation under the condition of cooperative self-defense coherent jamming, a model of cooperative self-defense coherent jamming was proposed based on the hovering track of the formation for stealth aircraft. Firstly, by analyzing the real-time attitude, the formation line-of-sight attitude angle was calculated. Then the dynamic RCS (radar cross section) sequence of formation was acquired based on the static dual-aircraft RCS database in the whole airspace. Finally, the instantaneous error and instantaneous detection probability of radar angle of stealth formation in normal flight and cooperative self-defense coherent jamming were compared and studied by using the angle tracking and detection mechanism of mono-pulse radar under the combined action of target echo signal and coherent jamming, and based on the corresponding joint signal-to-interference ratio analysis model. The simulation results show that the formation self-defense coherent jamming can effectively deceive the monopulse radar angle by 0.26 degrees and reduce the radar detection performance by 34.97%, effectively reducing the loss rate during formation voyage.