The formula of target tracking Bayesian Cramér Rao Lower Bound (BCRLB) in the range direction is derived,and the BCRLB in the range direction is used as a quantitative indicator of target tracking performance.For dual aircraft target tracking scenarios,BDWF,a BCRLB algorithm based on range direction Weighted Fusion is proposed using interactive multi-model Kalman Filter (KF).The simulation experiment shows that:1) The target tracking trajectory of the proposed algorithm fits well with the real trajectory,and the Root Mean Square Error (RMSE) during the tracking process can quickly converge to a stable value;and 2) Compared with the target tracking algorithm based on signal-to-noise ratio weighted fusion,the target tracking accuracy of the proposed algorithm is higher.