The invention discloses a norm constraint strong tracking cubature kalman filter method for satellite attitude estimation. The norm constraint strong tracking cubature kalman filter method comprises the following steps: 1, acquiring output data of a gyro and a star sensor; 2, determining state variables and measuration amount of a satellite attitude estimation system; 3, performing cubature kalman filter time updating and measuration updating at the moment of k to obtain one-step state prediction variance, one-step measuration prediction variance and cross covariance; 4, using a multiple gradual-fading factor for correction of the one-step prediction variance; 5, performing cubature kalman filter measuration updating again, acquiring state variance and state estimation variance at the moment of k +1; 6 if K + 1 = M (M is end moment of an attitude estimation nonlinear discrete system), outputting attitude quaternion and gyroscopic drift of state estimation of the moment of k +1 to complete the attitude estimation, if K + 1 < M, and k = K + 1, repeating steps 3, 4,and 5. The a norm constraint strong tracking cubature kalman filter method has the advantages of high estimation accuracy and strong robustness.