Box-like components are the component class with the complexity in structure and shape, and required premium quality on the machined surfaces, and with difficulty in design and manufacturing. In Euclid Space, a 3D modeling with collection of feature information based mainly on the CSG fundamental geometric element method and topological relationship was presented, with fundamental geometric element set, the topological relationship tree and datum system of fundamental geometric elements, and Boolean operations and linking, for CSG modeling of common box-like components. Details were also given to the study and construction of 9 modules for feature information collection. CSG modeling and collection of feature information of a base-box of reduction unit were put forward, as an example. The initial application of the system has shown that it was of simplicity, intuition, and effectiveness, with plenty feature pieces of feature information. It is satisfactory to design digitally even more complicated box-like components, and build up the information base for the following digital engineering with the current system.