Based on the optical transmission theory of multi-layer phase screens, a numerical model including the optical transmission process, layered atmospheric, continuous predicted phase screens, anisoplanatic imaging of the solar extended target was established, then analyzed and verified from the aspects of phase structure function, atmospheric coherent length and anisoplanatic angle. Under H-V 5/7 and H-V 10/10 turbulence models, the absolute errors of atmospheric coherent length and anisoplanatic angle are within 0.02 m and 0.3″ respectively. The results show that the statistical characteristics of the numerical model in time and space meet the practical application requirements, which provides a reliable model for the study of the effect of anisoplanatic errors on the solar image stabilization and adaptive optical system.