Glass fiber separator paper is made of glass fiber with a diameter of 3 μm-5 μm and is manufactured by wet process.The product has good chemical stability, good consistency, good temperature resistance and high safety. It has the function of preventing the short circuit of the positive and negative electrodes and absorbing the required electrolyte. The product effectively improves the energy density and charge-discharge performance of lithium/thionyl chloride battery（Li/SOCl2）.