Since the emergence of software engineering in the late 1960s, require-ments analysis has always been an important theme of software development. In the process of software development, many people are needed to coop-erate to ensure the stability and reliability of the software. According to the degree of formalization in the software development process, software en-gineering methods can be divided into three types: non-formal, semi-formal and formal. In object- oriented software development, UML has become a de facto modeling standard. However, although UML is intuitive and easy to understand and apply, it has inaccurate semantics, and UML is a semi-formal modeling language that cannot be formally verified. Event-B is a formal method based on a large number of mathematical predicate logic, which is accurate but difficult to understand and apply. Therefore, how to combine the advantages of UML diagrams and Event- B methods is the focus of re-search.