The present invention relates to a UV-cured multi-component polymer blend electrolyte, lithium secondary battery and their fabrication method, wherein the UV-cured multi-component polymer blend electrolyte, comprises: A) function-I polymer obtained by curing ethyleneglycoldi-(meth)acrylate oligomer of formula 1 by UV irradiation, CH.sub.2.dbd.CR.sup.1COO(CH.sub.2CH.sub.2O).sub.nCOCR.sup.2.dbd.CH.sub.2 (1) wherein, R.sup.1 and R.sup.2 are independently a hydrogen or methyl group, and n is an integer of 3-20; B) function-II polymer selected from the group consisting of PAN-based polymer, PMMA-based polymer and mixtures thereof; C) function-III polymer selected from the group consisting of PVdF-based polymer, PVC-based polymer and mixtures thereof; and D) organic electrolyte solution in which lithium salt is dissolved in a solvent.