The paper focused on the errors and their effects existing in the process of semi-strapdown stabilized platform design for seeker. Firstly, the control models of semi-strapdown platform angular velocity and frame angle were built based on the space angle relationship and quaternion method separately. Then, taking angular velocity command transfer, angular velocity calculation and matched filtering as the main error source, the influence mechanism of stabilized platform control and the extraction accuracy of angular velocity information were analyzed, and the simulation was carried out. The results showed that the platform framework angular velocity measurement error was hardly affected by other error sources, and the measurement error of line of sight angular velocity was greatly influenced by the velocity measurement error of position sensor after differential. The stability performance of semi-strapdown seeker mainly depended on the design of correction control loop and matched filter, while the matched filter would determine the precision and isolation levels of the stability of the platform.