The concept of cognitive testability, which embodies the requirements of equipment development, network and intelligence, is the new development of equipment support theory based on information technology. The concept and principle of the cognitive testability, the prognostics and health management (PHM) and the reliability centered maintenance (RCM) are introduced; the difference between cognitive testability, RCM and PHM is analyzed; and the index system of the cognitive testability is introduced briefly. The necessity and feasibility of the cognitive testability are expounded. Cognitive testability is the future development direction of equipment testability and will produce a far-reaching impact on the development of equipment.