A novel single-camera two-dimensional digital image correlation method based on photogrammetry correction is developed for the situation that the camera axis is not perpendicular to the surface of the specimen. Before deformation, at least three control points (circle mark point) are placed on the specimen surface, and the three-dimensional (3D) coordinates of the control points are measured by the photogrammetry. Then the camera orientation is calculated by the space resection method, and a control plane is obtained by fitting the control points. During deformation process, for each point in the image matched by digital image correlation, its corresponding 3D point is acquired by intersecting between the point ray and the control plane. Using this method, not only the measurement error introduced by slant axis of the camera is corrected, but also the displacement in millimeters rather than in pixels can be gained directly. Experimental results comparing with the existing 3D digital image correlation method show that, the displacement measurement accuracy by the proposed method is better than 0.04 mm, and the strain measurement accuracy is better than 0.5%.