Abstract: Ecological environment quality is a key indicator for measuring the harmony between humans and nature, and moreover, a core element determining whether a region can achieve sustainable development. Therefore, this study utilizes the Google Earth Engine (GEE) cloud platform for long-term, large-scale analysis. Combined with the Remote Sensing Ecological Index (RSEI), it conducts an in-depth investigation into the spatiotemporal changes of EEQ. Taking Anhui Province as a case study, the RSEI from 2003 to 2023 was extracted based on the GEE platform. The Theil-Sen Median trend analysis and Mann-Kendall test were employed, and the optimal parameters-based geographical detector model was used to analyze the changes and driving factors of EEQ in Anhui Province. The results indicate that: (1) Over the past 20 years, the RSEI in Anhui Province showed a fluctuating upward trend temporally, and a spatial distribution characteristic of "low in the north and high in the south, " with significant spatial heterogeneity. (2) Regarding the future change trend of RSEI, the EEQ in Anhui Province is still predominantly projected to improve. Most areas in the south show a highly significant increase, while northern areas also show a non-significant increasing trend. However, a few central areas exhibit a significant decreasing trend. (3) Concerning the driving factors of RSEI changes, the q-values under the interaction detection of various factors were significantly greater than those under single-factor detection. In 2003, the interaction between NDVI and annual precipitation was the strongest (q = 0.5491). In 2008, the interaction between average temperature and NDVI was the strongest (q = 0.4260). In both 2013 and 2018, the interaction between NDVI and land use type was the strongest (q = 0.5115 and 0.4325, respectively). In 2023, the interaction between NDVI and annual precipitation was again the strongest (q = 0.4680). Overall, the ecological environment quality in Anhui Province exhibits a positive developmental trend, although regional imbalance remains a prominent shortcoming. In the future, it is necessary to adjust industrial layouts and policies according to local conditions to promote the synergistic development of ecology and economy.