The invention discloses an occlusion region detection method based on an image sequence optical flow and a triangular mesh. The occlusion region detection method comprises the steps of: calculating an optical flow between two continuous frames of an image sequence; carrying out Delaunay triangular mesh generation on a first frame image; calculating brightness variations of image pixel points and triangular regions between the two frames of images; looking for corresponding triangular regions of a second frame image according to the triangular regions of the first frame image, detecting whether an embedded pixel point exists in the corresponding triangular regions of the second frame image, and determining an occluded triangular region; determining that the embedded pixel point is occluded or the triangular region is occluded according to brightness variations of the embedded pixel point and the triangular region; and traversing all the triangular regions in the images so as to detect occlusion regions of the whole image. Compared with the existing method, the occlusion region detection method has higher precision and reliability of occlusion detection.