This paper presents a coarse-to-fine combined method for dealing with large displacement situations caused by low speed of frame rate in microscopic video sequences. Motion image estimation method utilizes the modified block matching method based on image warping to perform a wide range of changes in the amount of search comparison, and then using the optical flow method to fine adjustment pixel by pixel, to complete the overall precision of the estimation. In the evaluation experiment, we have compared both current optical flow and proposed method by testing them with simulated vessel images, the results of the estimation is quite accurate.