The present disclosure provides a photochromic nanomaterial capable of blocking ultraviolet rays with a general formula of MaObXc, a production method and use thereof, wherein the M, O and X and a, b and c are as defined herein. The nanomaterial may be prepared by the following method: heating a mixture of an M-containing cation source compound, a polyol, a surfactant and first solvent under agitation, to obtain a hot first solution; mixing an X-containing anion source compound and a second solvent, to obtain a second solution; injecting the second solution into the hot first solution, to perform a reaction and obtain a reaction mixture; and subjecting the reaction mixture to post-treatment. The nanomaterial of the present disclosure can block 80% or more of UV rays, in particular, may change to a transparent dark color and reduce the transmittance under irradiation by strong light, whereas may restore colorless transparent state under irradiation by weak or non-strong light. Additionally, the present disclosure may have following features: a simple processing flow, low cost, high productivity, applicability in the industrial production, etc.