Nickel?iron (NiFe)?based transition metal catalysts have garnered significant attention in recent years for their excellent electrocatalytic performance,particularly in the oxygen evolution reaction (OER).However, the catalytic efficiency of NiFe?based transition metal catalysts still has a certain gap compared with precious metal Ru or Ir, so it is necessary to modify it.Research has shown that defect engineering can effectively enhance the OER catalytic activity of NiFe?based transition metal catalysts.The types of defects in NiFe?based transition metal catalysts, the characterization methods, and the methods for constructing defect materials are summarized, and an overview the research progress of the OER study of defect?type NiFe?based transition metal catalysts is given; the challenges of defect engineering to improve the OER performance are discussed and prospects for future development are proposed.