Abstract: The angle of the image rotation was studied which was caused by the movements of two frames of polar coordinates direct stable platform and indirect stable platform with four reflected mirrors. The result shows that both the movements of pitching-frame and rolling-frame cause the image rotation. The angle of image rotation of indirect stable platform which was caused by rolling-frames increased when the abaxial angle increased. When the abaxial angle was small, the angle of image rotation of indirect stable platform which was caused by rolling-frames was also small. The angle of image rotation of direct platform was direct ratio with the tangent of the angle of rolling-frame and was inverse ratio with the cosine of the angle of pitching-frame. The result of simulation shows that the angle of image rotation of indirect stable platform with four reflected mirrors was smaller than the direct stable platform and has lower influence on imaging.