In order to gain a comprehensive understanding of the vegetation ecological status of the Taihangshan-Yanshan Mountains Integrated Area in China, this study constructed an innovative Vegetation Ecology Index (VEI) that reflects both vegetation productivity and vegetation cover. This index has immeasurable guiding significance for measuring the superior and inferior status of the ecological environment. In this study, data from the Google Earth Engine (GEE) cloud platform was selected for analysis, covering the period from 2003 to 2021. This was done in order to gain a deeper understanding of the spatial and temporal change characteristics of the Vegetation Ecology Index (VEI). In order to study the changing law of the vegetation ecological index, a number of analytical techniques were applied, including slope trend analysis, coefficient of variation analysis and correlation analysis. These methods facilitate the revelation of the temporal and spatial patterns of vegetation VEI change. It was found that the vegetation VEI exhibits certain temporal and spatial change patterns within the Taihangshan-Yanshan Mountains Integrated Area. On this basis, the effects of climatic factors such as temperature and precipitation on the changes of vegetation VEI were further analysed. The results show that: (1) Between 2003 and 2021, the multi-year average value of the vegetation ecological index in the Taihangshan-Yanshan Mountains region of China reached 0.526. In general, the vegetation ecological index shows a trend of gradual decrease from the north to other directions. This distribution pattern is correlated with the altitude distribution. (2) During the period from 2003 to 2021, the vegetation ecological index of the study area showed an overall decreasing trend, with an average annual decrease rate of approximately 0.0017 per year. During this period, only 36.71% of the areas exhibited an increase in the vegetation ecological index. (3) During the study years, approximately 76.96% of the areas exhibited a stable change in the vegetation ecological index, with the majority of the areas demonstrating this pattern. The vegetation growth conditions remained relatively stable throughout the study period. (4) The analysis of a large amount of data revealed that the effect of the average annual temperature on the vegetation ecological index of the study area was more significant than the average annual precipitation. The findings of this study not only provide a valuable theoretical foundation, but also have significant implications for the assessment of ecological and environmental conditions, the rational allocation of resources, and the formulation of regional environmental and socio-economic development strategies in the Taihangshan-Yanshan Mountains.