Abstract: China is a major producer and consumer of vegetables, and the application of large amounts of nitrogen fertilizer is a crucial method for farmers to enhance both the yield and quality of vegetables. However, excessive nitrogen input leads to low nitrogen use efficiency (NUE) in vegetable planting systems, which not only undermines agricultural productivity, but also contributes to environmental issues such as soil degradation and water pollution. NUE serves as a key indicator of effective crop production, offering insights into practices that can minimize environmental impacts while maximizing output. Therefore, clarifying the current NUEs of vegetable planting systems and improving them is imperative for sustainable agricultural practices. Despite its importance, current data on the NUE of different vegetable production systems and vegetable types in China are unclear, and there is a lack of comprehensive analyses of its driving factors and improvement methods. Therefore, by collecting 1 386 observations (1 067 from open-air and 319 from greenhouse vegetable planting systems) from relevant field experiment literatures from 2010 to 2020, we analyzed NUE and its driving factors in China’s current open-air and greenhouse vegetable systems. A random forest model was used to identify and rank the importance of the different driving factors influencing nitrogen efficiency. The effects of various management practices on NUE were evaluated quantitatively using a meta-analysis. Our findings indicated that the current average nitrogen application rates for open-air and greenhouse vegetable systems are 227.2 (95% confidence interval of 218.9–235.5) kg(N)·hm⁻² and 361.5 (95% confidence interval of 336.8–386.1) kg(N)·hm⁻² per growing season. Correspondingly, the NUE values in these two systems were 27.8% and 23.2%, with range of 26.8%–28.8% and 21.6%–24.6%, respectively. Overall, the nitrogen application rate in greenhouse systems was 59.1% higher than in open-air systems; however, the utilization rate was 16.8% lower. The results of the random forest analysis indicated that in open-air systems, the nitrogen application rate contributed the most to NUE (24.0%), followed by sunlight duration during the growth period (10.7%), with soil total nitrogen content contributing the least at 2.9%. In the greenhouse systems, the nitrogen application rate was the highest contributing factor to the NUE (32.6%), followed by soil total phosphorus content (15.8%) and soil organic matter content (11.4%); soil pH contributed the least, at only 1.9%. A meta-analysis showed that the combined application of phosphorus and potassium fertilizers was the most effective way to improve NUE in open-air systems, followed by slow-release fertilizers, which enhanced NUE by 66.6% and 53.0%, respectively. In the greenhouse system, using both urease and nitrification inhibitors significantly improved NUE by 69.9%, followed by a reduction in nitrogen application (57.1%). Although the current NUEs of vegetable planting systems in China has increased compared with previous studies, efforts should continue to optimize nitrogen application rates and select comprehensive nitrogen management strategies based on the type of vegetables to improve NUE and mitigate environmental impacts in the future. The results provide data and technical support for decision makers in optimizing nitrogen management strategies and enhancing the environmental sustainability of vegetable production systems.