Abstract: Aiming at the problem of tiny object detection in stare observation image sequence, a new method based on frequency feature accumulation was proposed. First, star matching and difference of neighbor frames were used to eliminate background of images, and then by analyzing time-frequency feature, the method for accumulating frequency feature of image was applied in tiny object detection. The experiment shows that the method proposed can increase the signal-noise ratio (SNR) of image by 3 times, and favors tiny object detection.