Based on unparaxial diffraction theory, the imaging properties of spheric optical array with large size and large radius of curvature are analyzed in this paper. This theoretical model develops the paraxial theoretical model mainly in two aspects. First, it shows that not all, but only those kinds of optical arrays which satisfy certain conditions have non-Gaussian images, however, the paraxial shows that all kinds of optical arrays have non-Gaussian images. Secondly, it shows that various kinds of optical arrays have different imaging properties, but paraxial theoretical models show that all kinds of optical arrays have the same imaging properties. Moreover, by this theoretical model some experiments can be explained which cannot be explained by the paraxial. However, when the paraxial approximation is employed, the results from these two theoretical models will be the same. Furthermore, we numerically simulate the process of beam propagation in the optical array system without distorted media, and obtain the 3D intensity distribution on each receiving plane. The numerical results in this paper agree with our theoretical analysis.