The stabilization accuracy is one of the key performance indicators of electro-optical pod, and the research on the measurement of line of sight stabilization accuracy is significant for the measurement and acceptance of electro-optical pod. Combined with coarse and fine platform stabilization of electro-optical system, a measurement method of stabilization accuracy based on time/frequency domain analysis was proposed. By collecting the data of inertial angular-rate sensor and optical compensation elements under random vibration environment, the angular rate, image jitter and probability distribution of image drift were obtained based on the signal time-domain analysis. Based on the signal frequency-domain analysis, the power spectral density of line of sight angular position signal was obtained. The frequency band stabilization accuracy contribution was proposed, which could evaluate the influence degree of different frequency bands on stabilization accuracy. The efficiency improvement with two-level stabilization was used to evaluate the improvement degree of two-level stabilization in different frequency bands on system stabilization performance. This method can intuitively reveal the image jitter and probability distribution, and give the frequency factors affecting the stabilization accuracy of line of sight, which has important engineering application value for guiding the design of electromechanical system.