It is significant for constructing real corn leaf model by extracting midvein from 3-D point cloud model. Three algorithms, including curvature computation of meshes, parameterization of meshes and skeleton extraction of point cloud, were used to extract midvein from 3-D point cloud model. The whole algorithm was consisted of three steps, including incomplete 3-D point cloud extraction of midvein, complete point cloud extraction of midvein and 3-D midvein reconstruction. Through experiments on different kinds of corn leaves, it indicated that the proposed algorithm could extract the midvein of corn leaf faithfully with less runtime.