Nitrogen is a fundamental macronutrient essential for vital processes such as photosynthesis, protein synthesis, and nucleic acid synthesis in plant production. However, current fertilization practices often result in low nitrogen use efficiency, leading to both economic losses and serious environmental issues. Deep nitrogen fertilization involves placing nitrogen at greater depths closer to the plant root zone, which can enhance nitrogen uptake by plants while significantly reducing losses through surface volatilization and leaching. This article discusses the definition, significance, and impact of deep nitrogen fertilization on agricultural production, comparing it with traditional surface fertilization methods. Additionally, it provides analysis of application techniques and optimization, advantages, challenges and risks, as well as application areas and case studies. In conclusion, given the positive effects of deep nitrogen fertilization on plant growth, yield, nitrogen use efficiency and greenhouse gas emissions, it should be widely adopted in agricultural production.