Abstract: The integrated closed fuel cycle fast reactor nuclear energy system, referred to as the integrated fast reactor (IFR), represents an advanced stage in the development of nuclear fission energy. To align with its positioning as an advanced nuclear energy system and guide subsequent design and technological research, research on general design requirements should be conducted based on the characteristics of the integrated fast reactor and user needs. The international evaluation of the fourth generation nuclear energy system has established the relevant methodology. Key aspects of the evaluation framework for generation Ⅳ nuclear energy systems were integrated in this paper, including economic performance, safety, sustainability, and nonproliferation, with a focus on design-related user requirements. It proposes general design requirements for an integrated fast reactor, setting specific design objectives and target specifications to guide the development of integrated fast reactor designs.