Extraction method for special test data of visual inspection system

The invention discloses a method for extracting special test data of a visual inspection system. A data matching identifier exists before or after special performance index data in a work log of the special test data of the visual inspection system; comprising the following steps: 1) constructing a zero-width assertion regular expression on the basis of a historical test log in combination with a relative position of a data identifier and special performance index data, associating the zero-width assertion regular expression with a visual inspection system and a test item, and constructing a regular expression library; 2) automatically extracting data by using the regular expression library through the following steps: (1) obtaining a test log after a special test is completed; (2) selecting a visual inspection system and a test item to which special test data belongs, and calling a required zero-width assertion regular expression from a regular expression library; and (3) extracting data in the test log by u