Abstract: A rate gyro adaptive weighting method is proposed for the problem that the serious coupling of elastic vibration signals and rigid-body signals in the feedback control loop of flexible launch vehicles will significantly reduce the stability of the attitude con? trol system. The method can be applied to the cases where there are deviations in the shape slope and frequency of elastic vibration. The rate gyro observation signal is converted into a frequency domain expression， and the interpolated discrete Fourier transform method is used to identify the elastic frequency. An adaptive updating algorithm for the rate gyro weighting coefficient matrix is de? rived based on the frequency domain， which eliminates the elastic vibration signals of each order in a stepwise manner. A simula? tion calibration is carried out under different cases of deviation. Simulation results indicate that the rate gyro adaptive weighting method can realize significant suppression of elastic vibration signals in the rate gyro measurement signals and reduce the adverse ef? fect of elastic vibration signals on the stability of the attitude control system from the source. Thus the performance of the launch ve? hicle attitude controller is improved and the difficulty in the controller design is reduced.