In this paper, we present a new hand shape recognition algorithm based on Delaunay triangulation. When collecting hand shape images by a non-contact acquisition equipment, the degree of stretching of fingers may cause finger root contour deformation, which leads to unstable central axis and width features. Thus, we propose to form a more robust and non-parametric finger central axis extraction algorithm, by using a Delaunay triangulation algorithm. We show that our robust algorithm achieves the recognition rate of 99.89% on our database, while the mean time of feature extraction is 0.09 s.