The accuracy of paper duplicate checking system varies with system brand, algorithm and database. At present, there are paperfree, papertime and so on. Widely used for duplicate checking and oil paper of the first draft. Com, VIP and Wanfang are widely used in the final draft. The accuracy of the duplicate checking system is relative, and no system can completely guarantee the absolute accuracy of the detection results. Therefore, when using any paper duplicate checking system, we should be cautious about the test results and modify and improve them according to our actual situation.