Abstract: The inherent structure resonance has an impressive influence on the bandwidth of the optoelectronic stabilized tracking system. Aiming at the problem,a method for controlling the bandwidth expanding under structure resonance was proposed. In the method, the measurement of frequency characteristic and the least squares parameters identification algorithm were utilized. The results of experiment show that，by the method proposed in the paper, the resonance peak can reduce to 1/3 in speed closeloop and the control bandwidth can increase to about twice of the former, which prove that the method can suppress the structure resonance efficaciously, thereby improve the system control bandwidth, as well as ensure the system stability.