Nitrogen oxides (NOx) are the long-term focus of air pollution control, the technological core of industrial mainstream selective catalytic reduction of NOx with ammonia is deNOx catalyst, and the research and development of environmentally friendly and highly efficient deNOx catalysts is a common requirement of the world’s environmental protection. The background of deNOx demand, the application status of deNOx catalysts and existing problems are briefly described, and the research progress of three types of deNOx catalysts, including noble metals, metal oxides and ion-exchanged zeolites are summarized. The development progress of the environmentally friendly rare earth-based deNOx catalysts and the research progress on non-toxic SCR catalysts for marine deNOx are highlighted. The rare earth-based deNOx catalyst independently developed by China is the second flue gas deNOx catalyst for large-scale industrial application, which has been designated as a substitute for the vanadium-based catalyst by the three state ministries and the national development and reform commission, and will become a key material for industrial deNOx applications in the future. From the two aspects of ultra-low NOx emission demand driven by different industries and the difficulty of deNOx in severe working conditions, the new challenges of deNOx catalysts are discussed. The ultra-low temperature deNOx catalysts with strong anti-water and sulfur dioxide poisoning abilities, the high temperature deNOx catalysts with high hydrothermal stability, and the new multifunctionalization of deNOx catalysts for treating other pollutants, are the focuses of future development.