Abstract: Ammonia is not only an important chemical raw material and a good hydrogen carrier,but also its properties as a carbon-free fuel has attracted widespread attention. A synthetic ammonia process with low energy consumption and high efficiency is the key to realize the application of ammonia as fuel. In this paper,the development of ammonia synthesis process was described,and the new development of ammonia synthesis process driven by heterogeneous catalysis and external field forces such as light and electricity based on Haber Bosch process was summarized. The latest research results of chemical looping ammonia synthesis were mainly introduced,and the research direction was prospected. Due to the harsh reaction conditions of the traditional Haber-Bosch process and the contradiction between thermodynamics and kinetics,researchers have been trying to explore sustainable and environmental-friendly ammonia synthesis technology. With the progress of catalytic science and surface science,people have a deeper understanding of the reaction mechanism of ammonia synthesis and the physicochemical properties of catalyst,which provides valuable reference information for the development of " green" ammonia synthesis process. For example,in order to improve the performance of transition metal catalytic ammonia synthesis,it is necessary to avoid the linear rela-tionship between surface species adsorption energy. In addition,the reaction rate and mechanism of light and electro-catalytic synthesis of ammonia using renewable energy as an energy source can be effectively affected by the help of external field effects. The development of chemical looping technology provides a new idea for ammonia synthesis process. The process of ammonia synthesis can be decoupled into two or more step-by-step reactions of nitrogen absorption and nitrogen desorption,which can better alleviate the contradiction between thermodynamics and kinetics of ammonia synthesis and avoid competitive adsorption of reactants. At the same time,each step-bystep reaction can be optimized respectively to achieve the best reaction effect of the whole chemical looping ammonia synthesis process. In the future,the cost and energy consumption of carbon-based chemical looping ammonia synthesis process can be reduced by using solar energy for energy gathering,biomass carbon as carbon source,and analyzing the economic feedback of the chemical looping ammonia process to guide the optimization of the process flow.