The urban heat island effect (UHI) is one of the hot issues of urban ecological environment that people are most concerned about. It is of great significance to explore urban heat island effect and its impact factors for the construction of eco-city development. In this paper, the effect of aerosol optical depth (AOD) and impervious surface percentage (ISP) on urban heat island was investigated via the urban heat island footprint (UHI FP), Getis-Ord G^*, Pearson correlation and AOD quantitative attribution analysis method. The results show that between 2000 and 2018, the day/night UHI FP in the urban area of Xi'an and Xianyang (Xixian) increased significantly and the influence of UHI was enhanced year by year. The day/night UHI FP of Xixian was wider than that of Baoji, and the UHI phenomenon of Xixian was more obvious. The UHI FP of Xixian at night was almost entirely dominated by the high land surface temperature (LST) value, and UHI at night was more obvious than during the day. Although Baoji's UHI FP did not increase or decrease significantly, the day/night LST sub-heat zone area within UHI FP of Baoji increased gradually, and UHI significantly increased. The impervious surface percentage in the urban area of Xixian, Baoji was significantly positively correlated with night urban island intensity (ΔT). The difference between urban and rural aerosol optical depth (ΔAOD) was also significantly negatively correlated with night ΔT. ΔAOD in the Xixian was negative, and the average contribution was (0.41±0.14) ℃. The ΔAOD of urban and rural values in Baoji were positive, and the average contribution was (-0.26±0.25) ℃. In general, the expansion of urban impervious surface will further worsen UHI, and the increase of AOD in the urban area will inhibit UHI formation. However, UHI intensity of Xixian and Baoji is still increasing year over year due to the comprehensive influence of other factors.