Abstract: As the high precision aircraft such as the modern spacecraft becomes more complicated,the safe operating problem also becomes more and more significant.FDIR (Fault Detection,Isolation and Recovery) techniques are important guarantee of the reliability of spacecraft.Based on Kalman filtering estimation algorithm,a kind of FDIR method based on hierarchic alliance of filter family is proposed.According to the concept of the backup filter,this method constructs a kind of dendriform hierarchic alliance structure of fusion filter.On the basis of that,the multilevel FDIR can be designed and performed.A simulation example of INS/GPS/Doppler integrated navigation system illustrates the feasibility and effectiveness of this method.The multi sensor information processing technique based on the hierarchic alliance filter structure can resolve the limitation of the centralized Kalman filter and the normal federated filter,and has significance to enhance the fault to lerant ability of the system.Fault Detection,Isolation and Recovery) tech