Saline soil is widely distributed and of various types in China，which poses a challenge to agricultural production.Improper agricultural management aggravates soil salinization.Salt stress not only reduces the osmotic potential of soil water and produces ion toxicity，but also seriously affects nitrogen cycling and crop absorption，resulting in a decrease in nitrogen nutrient utilization use efficiency.The decrease of nitrogen use efficiency will not only seriously affect crop growth，but also pollute the environment.Therefore，it is particularly important to improve the nitrogen availability in saline soils.In this review，the particularity of the nitrogen conversion process in saline soils was summarized，and the effects of the interaction of the factors on the nitrogen conversion process and soil nitrogen availability were analyzed from the perspectives of salinity，soil pH，water content，soil enzyme activity and microorganisms，etc.The research progress of soil regulator，engineering improvement and biological improvement technology in the current research on saline soil improvement was summarized.The advantages and disadvantages of different technologies were analyzed，and the main directions and technical measures for improving nitrogen availability in saline soil in the future were prospected，in order to provide theoretical basis for improving nitrogen availability in saline soils and promote sustainable agricultural development.