Aimed at the problems that the stability region of the system corresponding to parameters such as DC side filter is difficult to determine and select the main factors of parameters in the multielectric aircraft power system, and the main parameter participating factors and the long stability time are also difficult to select, a method based on eigenvalue participating factors is proposed. dq transformation method is used to carry out the equivalent transformation of the aircraft power system, and its mathematical model is established. Taylor series is used to linearize the small signal, and a linear small signal analysis model of its dynamic characteristics is obtained. And then, the eigenvalue method is used to analyze the stability of the system, and the change trend of the stability when the parameters change is obtained through its participation and participation factors, determining the stability boundary of the system and predict the position of the unstable point. Through Matlab/Simulink, the system simulation model is established and the simulation analysis is carried out. The results show that the stability analysis of the power system by using the participation factor could significantly shorten the time to select the dominant parameters, clearly and 〖JP2〗quickly display the stability domain and instability point of the system under different dominant parameters.