To deal with the problems of the increased calculation complexity and decreased real-time performance due to the introduction of the fading factor in Strong Tracking Cubature Kalman Filter (STCKF) algorithm, a simplified STCKF algorithm is proposed.By proving that the time update of STCKF algorithm is consistent with one-step prediction process of Kalman Filter (KF) algorithm, the simplified STCKF algorithm is derived and the complexity of the algorithm is analyzed.The simulation results show that the simplified STCKF algorithm can effectively improve the real-time performance of the algorithm while keeping the filtering accuracy.