1. A dynamic calibration method for video capture device, comprising: providing at least one video capture device for capturing at least one initial image; panning or tilting said video capture device for capturing at least one successive image with different angles; extracting at least one initial feature point from said initial image, and extracting at least one feature point from said successive image, wherein said feature point is corresponding to said initial feature point; and acquiring variations of a pan angle and a tilt angle of said video capture device according to the displacement between said initial feature point and said feature point.