为了探究西安市机动车保有量对城市空气污染的影响，收集2014—2021年西安市机动车保有量与空气质量年度数据，建立机动车保有量与空气质量指数（Air Quality Index, AQI）、颗粒污染物（PM2.5, PM10）浓度以及气态污染物（SO₂, NO₂, CO）浓度之间的灰色关联模型，分别运用灰色绝对关联分析、灰色相对关联分析等方法分析了西安市机动车保有量与城市空气质量各监测污染物浓度之间的灰色关联度。结果表明：在机动车保有量与空气质量各监测污染物浓度关联度中，最大为NO₂的0.408，属于中等相关，其他都属于弱相关，最小为SO₂的0.201。总体上，西安市机动车保有量与城市空气质量各监测污染物浓度之间的相关性不强。因此，在西安市城市空气污染治理上，建议合理配置资源，提升治理效果，着重从工业污染等方面分析西安市空气污染问题。

In order to explore the influence of motor vehicle ownership on air pollution, taking Xi′an as an example, the annual data about motor vehicle ownership and air quality in Xi′an from 2014 to 2021 were collected. The grey correlation model between motor vehicle ownership and AQI(Air Quality Index), particulate pollutant concentration (PM2.5, PM10) and gaseous pollutant concentration (SO₂, NO₂, CO) was established. The correlations between motor vehicle ownership and the concentrations of various air quality monitoring pollutants in Xi′an were studied by grey absolute correlation analysis, grey relative correlation analysis and other methods. The analysis results show that among the correlations between motor vehicle ownership and the concentrations of various air quality monitoring pollutants, the maximum is 0.408 for NO₂, which is moderately correlated, the other two are weakly correlated, and the minimum is 0.201 for CO₂. In general, the correlation between motor vehicle ownership and the concentrations of monitored pollutants of urban air quality in Xi′an is not strong. Therefore, as for the urban air pollution control in Xi′an, it is suggested to properly allocate resources, improve the effect, and focus on the analysis of air pollution in Xi′an from industrial pollution.