The invention discloses a preparation method of ultraviolet-visible-near infrared light induced self-repairing nano composite hydrogel. The preparation method comprises the following steps: firstly, loading noble metal nanoparticles on the surface of metal oxide to form a metal oxide nano composite material; secondly, compounding a functional modifying body and the metal oxide nano composite material through a dynamic covalent bond manner; in the presence of a polymerizable monomer, taking the metal oxide nano composite material as a multifunctional crosslinking agent and an initiator; carrying out free radical polymerization reaction under the condition of light or heat and finally obtaining the nano composite hydrogel. According to the preparation method disclosed by the invention, a polymerization process belongs to uniform polymerization reaction, so that an inner network structure is relatively uniform. A multifunctional nano compound is introduced, so that the hydrogel can be self-repaired under the induction of near infrared light, visible light and ultraviolet light, and has a self-repairing function under a full spectrum.