Abstract: Saline-alkaline land is an important reserve resource of cultivated land. Organic fertilizer has abundant sources and broad prospects in saline-alkaline land improvement. This article comprehensively analyzes the progress of organic fertilizer in improving the physical and chemical properties, nutrients, soil microorganisms, and enzyme activity of saline-alkaline soil. The main mechanisms of organic fertilizer application in ameliorating saline-alkaline soil are: (1) Improving soil structure, increasing large particle soil aggregates, increasing soil porosity and permeability, reducing soil salinity; (2) Increasing the content of nutrients and organic matter, improving soil nutrients; (3) Optimizing the structure of soil microbial community, promoting the production of organic acids by microorganisms, and enhancing soil enzyme activity. It is recommended to strengthen the research and development of specialized functional organic fertilizers for saline-alkaline land, screen the suitable organic fertilizer application rates for light, medium, and severe saline-alkaline land in different regions, which would provide technical support for the improvement and utilization of saline-alkaline land.