Boron nitride nanosheets (BNNS) were modified by KH550 (fKH550-BNNS) and grafted with liquid crystal monomer 4,4'-diepoxybiphenyl (LC) for preparing boron nitride nanosheets grafted with liquid crystal monomer (LC-fKH550-BNNS). A self-healing polymer matrix (CTBE) with reversible cross-linking structure was prepared by using the non-covalent bond between magnesium ions and indole groups. Thermal conductive polymer composites with self-healing property (LC-fKH550-BNNS/CTBE composites) were obtained by high voltage orientation molding via filling LC-fKH550-BNNS with different content into CTBE. The highest thermal conductivity (TC) of LC-fKH550-BNNS/CTBE composites is 2.23 W·(m·K)?1 with 40wt% content of LC-fKH550-BNNS, and tensile strength and self-healing rate is 7.37 MPa and 71.57 %. This is related to the highly efficient thermal conduction pathway formed of LC-fKH550-BNNS by high voltage orientation molding, as well as the reversible cross-linking structure between Mg2? and indole groups that can be rapidly removed and re-established.