The recent progress on molecular beam epitaxy growth of SW/MW dual band HgCdTe on Si composite substrate are reported.The growth and characterization of the barrier layer are the key points of getting the SW/MW dual-band HgCdTe material on Si substrate with good crystal quality and parameter accuracy.After the optimization growth of the barrier layer,the diameter of the defect is less than 10μm and defect density is less than 2000 cm-3.The composition of barrier layer in dual band HgCdTe is obtained by the photoluminescence(PL) spectrum.