Abstract: The scanning mirror is a key component in strapdown optical systems for achieving continuous scanning imaging.The stability of the mirror's normal line under carrier vibration directly affects the performance metrics of the optical system. Taking a specific type of scanning mirror as the research subject, mechanical-electrical integration models and opto-mechanical integrated analysis models are developed from the two dimensions of servo control accuracy and structural dynamic response of the opto-mechanical system, analyzing the response of the scanning mirror's normal line under typical carrier vibration excitation within a 5~200 Hz frequency range. The analytical results indicate that the scanning mirror shaft model behavior is the primary cause of mirror normal line jitter. The scanning mirror group normal line stability experiment is designed, obtaining response curves for mirror jitter and cross-coupling control residual error under vibration conditions. A comparative analysis of experimental and analytical results indicates that the specular normal jitter curves obtained by the two methods are generally consistent. Under longitudinal, vertical and lateral vibration excitation, the errors are 36.12%、26.37% and 21.99% respectively, validating the accuracy of the analytical model. The research methodology and conclusions presented in this paper offer valuable references for evaluating and optimizing the normal line stability of scanning mirror assemblies in optoelectronic system under vibration effects.