The invention discloses a cross-linked polymer gel electrolyte membrane supported by a hydrophilic polytetrafluoroethylene microporous membrane. When the cross-linked polymer gel electrolyte membrane is prepared, firstly, methoxypolythylene glycol with double bonds and methyl acrylic glycidyl ester segmented copolymer are combined, ethylene glycol dimethacrylate, a thermal initiator and organic electrolyte containing lithium salt are added, stirring is conducted to form an even polymeric precursor solution; the hydrophilic polytetrafluoroethylene microporous membrane is immersed in the polymeric precursor solution and fully absorbs the polymeric precursor solution and is taken out, and the cross-linked polymer gel electrolyte membrane is obtained after cross-linked gelatinization is conducted. According to the cross-linked polymer gel electrolyte membrane, the preparation technology is simple, the electrolyte membrane is suitable for industrial production, a prepared cross-linked polymer gel electrolyte membrane system not only has a good mechanical property, but also has a good electrochemical property, an ionic conductivity at room temperature reaches up to 1.30*10-3 S cm-1, and an electrochemical stability window value can reach 4.5V. Lithium iron phosphate/lithium metal batteries assembled by the cross-linked polymer gel electrolyte membrane have good cycle performance under 25 DEG C and 70 DGE C.