The invention relates to a method for correcting the precision of the roll gap of a CSP wrapper roller. The method comprises the following steps: (1) manually correcting the diameter size of a core shaft; (2) correcting the pre-swell diameter of the core shaft by virtue of an automatic control program; and (3) correcting the deviation of the wrapper roller. According to the method, the problem that working roll gap of the wrapper roller is instable is solved, a steel blocking problem of a Masteel CSP wrapper roller is effectively solved, and the production stability of a rolling mill is improved.