The article presents the prototype of the computer simulator complex (CSC) developed for automated control of visual modelling skills of systems and processes in the training of engineering specialists in the field of food production. With the use of CSC, it is possible for teachers to create and students to perform exercises on analysing and building diagrams in various standards (in particular, UML). The key functionalities of CSC are: setting up exercises on analysis and construction of visual models by the instructor; formation of individual variants of exercises in accordance with the instructor's settings; execution of exercises by the student in a special interface, including the use of a graphical editor for building diagrams; automatic formation of a reference solution of the exercise and evaluation of the students' solution in accordance with the reference. The CSC prototype, implemented in the form of a web-based system, is used in Russian Biotechnological University when training students in the field of development of automated control systems for food production. The application of CSC simplifies the processes of knowledge control, collection and analysis of data on knowledge control, which contributes to the improvement of learning outcomes of specialists.