Abstract: The subject of research is the process of designing a conveyor belt. The authors consider parameterization in geometric modeling of parts and components of equipment and the creation of custom libraries in Compass 3D as a means of reducing the complexity and improving the quality of the design process. The preliminary design is the design stage of the development of design documentation and aims to determine the fundamental design solutions for a general idea of the device, operating principles and dimensions of the product. It is advisable to develop a preliminary design before the stage of developing a technical project and creating design documentation. Today, at all stages of work on the project, modern computer-aided design (CAD) systems are used, which not only accelerate the design process, but also make it possible to demonstrate to the customer the finished project at the stage of making technical decisions. This allows making timely changes in accordance with the requirements of the customer and to carry out high-quality preparation of the project for its implementation. The volume and time for further stages of work depend on the timing of the presentation of the preliminary design, therefore, the use of three-dimensional modeling parametrization in CAD is an effective way for designing engineering objects. Parameterization when working with 3D models allows you to get a set of typical product designs based on a once-created model by changing the set values of the variables, which significantly reduces the time spent on the project.