The invention discloses a multi-component complex phase nano boride, a corresponding ultra-high temperature oxidation-resistant coating and a preparation method, and belongs to the technical field ofultra-high temperature thermal protective coatings. The multi-component complex phase nano boride and the corresponding ultra-high temperature oxidation-resistant coating are composed of 3-20wt% of TiB2, 10-40wt% of SiC and the balance HfB2. A nano structure inside the nano HfB2-SiC-TiB2 coating can control the stress at the grain boundary so as to obtain a high-strength interface, inhibit dislocation movement in a fracture process, hinder crack growth and effectively improve the fracture toughness of the coating; a third phase of TiB2 is added for modification, and TiO2 with a low melting point generated in a service process of the coating can enhance the self-healing ability of an oxide film; and the coating can resist a temperature of more than 1800 DEG C and is more stable in performance, which can effectively solve the problems of poor fracture toughness and insufficient stability of the existing ultra-high temperature oxidation-resistant coating for an aircraft in a service environment.