A series of InSb thin films were grown on GaAs substrates by molecular beam epitaxy(MBE).GaSb/AlInSb is used as a compound buffer layer to release the strain caused by the lattice mismatch between the substrate and the epitaxial layer,so as to reduce the system defects.At the same time,the influence of different interface structures of AlInSb on the surface morphology of buffer layer is explored.The propagation mechanism of defects with the growth of buffer layer is compared and analyzed.The relationship between the quality of InSb thin films and the structure of buffer layer is summarized.Finally,the growth of high quality InSb thin films is realized.