Abstract: To depress the guidance message noise of air-to-surface semi-strapdown imaging seeker, the control loop model of stability tracking was established, the transform characteristic of various error and output was derived. The power spectrum response of main noise was obtained. Then, the weighted angular rate of line of sight was gained. In order to verify the validity of the weighted angular rate of line of sight, the simulation were completed in the guidance loop. The results show that the weighted method can effectively compressed the noise measurement information of seeker. The semi-strapdown TV seeker was achieved with semi-physical way, the double closed-loop was completed in TV seeker to make disturbance isolation and track the target. The methods for extracting guided information through weighted angular rate of line of sight and direct extraction methods were compared. The experimental results show that the weighted extraction method of line of sight angular rate noise variance is 0.098 ()/s, which is lower than the direct synthesis of noise of 46%. The weighted method can improve the problem of large semi-strapdown sight angular rate noise.