The invention relates to a macrolattice mismatch epitaxial material buffer layer structure containing a superlattice isolated layer and preparation thereof. N layers of strain-free superlattice isolated layer materials are inserted in a component gradual change buffer layer, wherein n is a natural number and is not smaller than 1 and not larger than 5. The preparation process comprises the following steps of: firstly, determining the parameters of growth temperature, beam source furnace temperature and other parameters; and then sequentially and alternately growing buffer layers with gradually increased strain capacities and strain-free superlattice isolated layer materials on a substrate by adopting a molecular beam epitaxy method until finishing the growth of a buffer layer reaching an expected strain capacity. The material contains the superlattice isolated layer and can ensure that relaxation can quickly and effectively occur to a macrolattice mismatch epitaxial material to release stress in the buffer layer so as to reduce the dislocation density of the epitaxial material on the buffer layer. Moreover, the uninterrupted growth of the material is carried out by adopting a conventional molecular beam epitaxy method, thus the invention has the advantages of easy control of operations, low cost, environmental protection, and the like.