Method for preventing chlor-alkali ion membrane from generating pocking marks

The invention discloses a method for preventing a chlor-alkali ionic membrane from generating pits. The method comprises the following steps: controlling the fiber relaxation gt in the chlor-alkali ionic membrane; 7% realization; the method for testing the fiber relaxation degree in the chlor-alkali ionic membrane comprises the following steps: (1) measuring the hydrolysis swelling ratio of a chlor-alkali ionic membrane precursor which does not contain reinforced fibers, wherein the swelling ratio (TD or MD) is equal to 100% * (size after membrane hydrolysis-size before membrane hydrolysis)/size before membrane hydrolysis; (2) calculating the limit displacement of the to-be-tested chlor-alkali ionic membrane precursor sample containing the reinforced fibers, and obtaining the tensile force at the limit displacement through the tensile curve, the limit displacement = the effective length of the tensile sample * the swelling ratio; and (3) calculating the fiber looseness in the to-be-tested sample of the chlor-