The invention discloses nano remelting layers on the surface of a TiBw-TC4 composite material and a preparation method of the nano remelting layers. The nano remelting layers are characterized in thatthe in-situ synthesized TiBw-TC4 composite material with a net structure is taken as a base material, the surface of the base material is rapidly melted through a defocused rapid scanning mode by anelectron beam and is solidified to for the plurality of remelting hardening layers, wherein the remelting hardening layers are composed of nanoscale titanium alloy martensite and a nanoscale TiB reinforcing body, the original plasticity and toughness of the material are still kept on the basis that the internal structure of the material is not damaged, so that the problem that the material rapidlycracks and fails is effectively solved, and the material has higher specific strength and surface performance and can be better applied to the fields of aerospace, metallurgy, chemical engineering, medical instruments and the like.