The air environment is a dynamic and complex system. The research results indicate potential directions and objectives for air quality management to achieve scientific management. Specifically, the correlation degrees of the first-classification, second-classification and third-classification of air quality are 0.674, 0.697 and 0.71, respectively. Correlation analysis is used to qualitatively determine that these three classifications correspond to first-level air quality in China’s air quality standard, and the correlation degree, which is the distance between the three classifications and the first-level air quality, is quantitatively determined. The results show that the air quality in this region in 2018 can be divided into three classifications, among which the relatively poor air quality in March, April and May is the first classification, the better air quality in August and September is the third classification, and the air quality in other months falls under the second classification.

Taking the air quality in Ningxia Province, China, as an example, according to China’s air quality standard, SO 2, NO 2, PM 10, PM 2.5 and O 3 are selected as evaluation indexes to perform the evaluation. To scientifically and reasonably evaluate air quality with a large amount of monitored data, this paper proposes a new evaluation method called ideal grey close function cluster correlation analysis ( IGCFCCA).

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