Abstract: Cities are the main sources of carbon emissions in the whole society, and urban spatial structure has an important impact on urban carbon emissions. In this paper, firstly, the evaluation index system of urban compactness was constructed, and the entropy method was used to measure the compactness of the city. Secondly, with the help of Kaya’s carbon emission identity,the carbon emission intensity of each city was calculated. Finally, the coupling coordination model and geographic detector were used to analyze the trend and driving factors of the coupling coordination between compactness and carbon emission intensity in Northwest China. The results showed that:（1） During 2006～2021, the urban compactness in Northwest China showed an upward trend as a whole, and the high-value areas of compactness were mainly concentrated in the provincial capitals of the five provinces, and the low-value areas of compactness were mainly distributed in small cities with low economic and population density, and Jiuquan City was in the bottom four for all years.（2） During 2006～2021, the carbon emission intensity in Northwest China showed a downward trend as a whole, with a large decline, and the high carbon emission intensity area gradually moved to the northwest, showing a spatial pattern of high in the middle and low on both sides.（3） The coupling coordination degree of urban compactness and carbon emission intensity in Northwest China showed a slight upward trend from 2006 to 2021, with an overall increase of 0.12, and the state finally reached primary coordination from the verge of coordination. According to the identification of the influencing factors of geographic detectors, the factor that has the greatest impact on coupling coordination is scientific and technological innovation, and the factor that has the least contribution to coupling coordination is employment level.