With the development of technology, internet technology is becoming more and more mature, so that users can choose different categories of information according to their needs and suitable for their own characteristics and preferences when surfing the internet, instead of having to passively obtain it. Therefore, when browsing information, users will choose websites that interest them or suit their characteristics and interests according to their own needs, and search engines will calculate the corresponding ranking according to the user's browsing information, and finally recommend the website to the target user. The application of recommendation technology in the field of information retrieval not only helps users to obtain useful content from the huge amount of data, but also improves the effect of search engine optimization. This paper introduces a recommendation model based on mathematical expressions and focuses on its role in modelling user behaviour, while the algorithmic process is also described in this paper.