In practical teaching, it is found that students' academic performance in basic courses is correlated to some extent. This paper takes the students' public course scores of 11 majors in a higher vocational college as the research object, and proposes a D-Apriori algorithm based on improved excellence rate and data integration. The new algorithm solves the problem of deviation in the association of excellent grades caused by different scoring standards of courses, and can more efficiently explore the association rules between excellent grades obtained by public basic courses. The relevant research results of this paper can provide reference for the teaching design of basic courses and the adjustment of teaching methods in higher vocational colleges, and provide reference and suggestions for the follow-up training and education of students.