Develop a high-strength PTFE base membrane with uniform strength, uniform thickness, and uniform pore size. The thickness of the membrane base material is uniform (the tolerance is controlled within 0.01 micron), the pore size is uniform (the tolerance is controlled within 0.01 micron), and the strength is uniform. These three uniformities are to ensure the tensile strength of the membrane. It is key for the stretched membrane to meet international standards.