Since the square root Cubature Kalman Filter is not robust and unable to give a quick response during target online maneuvering,an algorithm of adaptive Cubature Kalman Filter (CKF) is proposed,which uses the square root form of CKF for iteration,that is,SCKF.This algorithm introduces a strong tracking filtering algorithm into SCKF,and introduces a fading factor for detecting and restraining the filtering divergence,which effectively overcomes the problem that a standard filter cannot quickly and accurately track the spatial target during its maneuvering,and improves the numerical stability of spatial target location and tracking.Simulation result shows that: Compared with standard SCKF,the adaptive SCKF can effectively improve the robustness of maneuvering target passive locating and tracking,has higher filtering accuracy and stability,and good real-time performance,which can better accomplish the tracking task of spatial maneuvering target.