In order to adapt to the development of the times and the needs of modern warfare, and to improve the operational effectiveness of equipment, a concept of equipment support big data construction based on design for cognitive testability (DFCT) is constructed. Emphasizing the role of “information” in equipment support, cognitive testability extends the connotation of traditional testability. To evaluate the level of cognitive testability design, an evaluation index system is proposed that focuses on information acquisition performance, fault diagnosis performance, and predictive decision-making performance, and its specific meanings are explained. The results indicate that this design can provide design support for the establishment of equipment support databases.