Self-taught undergraduate graduation thesis needs to be checked to prevent academic misconduct. The duplicate checking of graduation thesis of self-taught examination mainly focuses on the abstract, text, ending, tables, formulas, pictures and quotations, among which the quotations need to be quoted reasonably according to the requirements of the school to avoid academic misconduct such as plagiarism. The duplicate checking system will compare the text of the paper to check whether there is plagiarism, repetition or improper citation. If the paper is found to be plagiarized or misquoted, it may be judged as academic misconduct, leading to failure, delayed graduation or even cancellation of student status. Therefore, it is suggested that when writing graduation thesis, we should abide by academic ethics and norms, complete the thesis independently, and pay attention to avoiding plagiarism and repeated quotations.