The glass fiber separator is made of glass fiber with a diameter of 0.6-3μm and is made by wet process technology. The product has good acid resistance, high porosity, small pore size, high liquid absorption rate, and low resistance. It has the functions of preventing short circuits and adsorbing the required electrolyte. Its free channel allows oxygen to be reconstituted into water on the negative electrode. There is no need to add water during use, and functions such as maintenance-free are realized.