Abstract: Operation environment of existing railway system is complicated, the operation demands is changeable, which result in the function requirement of train operation control and monitoring device(LKJ) change frequently. In order to manage the requirement properly and regularly, it is necessary to model the function of LKJ based on UML. This article analyzed the structure and function of LKJ, created use case model of system; by using class diagram, sequence diagram and state diagram in UML, analyzed the static structure and dynamic behavior for main operation scene of LKJ, established static model and dynamic model; verified the accuracy and completeness of the LKJ function model. By usin the LKJ function model, people can avoid the ambiguity of the LKJ functional requirements, which is conducive to the smooth development and maintenance.