Abstract: For the problem of data filtering processing in complex scenes such as multiple data rates, collaborative detection of sensors with different detection accuracy and target maneuver, etc. a multistage combined α -β filtering algorithm based on optimal iteration is proposed. For the data jitter problem caused by the switch of multimode filter, the original and independent optimal filter data are inherited by iteration mode in the framework of multistage optimal α -β filter, and the feedback of optimal filter data between different filters is realized, the problem of data jitter in mechanism is avoided. In addition, the closed-loop characteristic equation of the system is analyzed and the Routh-Hurwitz criterion of the continuous system is utilized, the necessary and sufficient conditions for the stability/convergence of the filter algorithm are established, and the selection range of the filter gain α、β are given, a more intuitive reference for the selection of the parameters of the multistage combined filter is provided. The simulation results verify the effectiveness of the optimal combined filtering algorithm.