The invention discloses a polymer solid-state electrolyte material and a preparation method therefor. The polymer solid-state electrolyte material is an organic-inorganic hybridized and crosslinked polymer solid-state electrolyte material which is prepared by performing ultraviolet light irradiation and crosslinking on reaction raw materials, wherein the reaction raw materials comprise silicon dioxide nanoparticles grafted with sulfydryl on the surface and double-band end-capped polyethylene glycol at the mass ratio of 1/2 to 1/20; and in addition, the content of sulfydryl component in the silicon dioxide nanoparticles grafted with sulfydryl on the surface is 1-50wt.%. By means of improvement of the whole technological process, the reaction conditions in each step and the like in the key preparation process, the organic-inorganic hybridized and crosslinked polymer solid-state electrolyte material is correspondingly formed; and compared with the prior art, the ionic electrical conductivity and mechanical performance of the composite electrolyte can be improved at the same time.