The design of the vertical spindle head, which is part of the modular technological equipment of horizontal drilling-milling and boring machining centers, is considered. Three-dimensional modeling of parts and assembly units of the spindle head has been performed in the environment of integrated CAD system KOMPAS-3D. The effectiveness of full-featured specialized applications in the design process of the structure main components in the KOMPAS environment is noted. Built-in “Shafts and mechanical transmissions” applications for creating a vertical spindle head model the design procedures in the shortest possible time are provide. An assessment of the forming spindle assembly dynamic functioning quality on which external loading acts, with probabilistic nature is made. The spectral analysis method is used to evaluate the dynamic characteristics of the structure under consideration.