The invention relates to a method for preparing function group-containing chiral borane with high optical purity. The diene ligand can be used as a catalyst in the asymmetric reaction of insertion of monovalent rhodium metal carbene to the boron-hydrogen bond of an amine-boron complex or N-hetercyclic carbene-borane in order to realize the method. The method has the advantages of mild reaction conditions, simple operation, good substrate applicability, and realization of preparation of alpha-carbonyl group-containing organic borane compounds with high optical purity under high yield and high stereoselectivity.