[Objective] In order to investigate the changes in ecological environment quality and its driving factors in the Yellow River Source Park of Three-River-Source National Park from 2000 to 2024, so as to provide a scientific basis for ecological protection and sustainable development in the region. [Methods] Based on Google Earth Engine platform, MODIS images were acquired and processed to construct the remote sensing ecological index for monitoring the ecological environment quality changes in the Yellow River Source Park from 2000 to 2024. The geographical detector model was utilized to quantitatively analyze the influences of climate, topography, and human activities on these changes. [Results] (1) From 2000 to 2024, the annual mean RSEI in the Yellow River Source Park ranged between 0.527 and 0.689, showing a fluctuating upward trend with an average increase rate of approximately 0.0031 per year. Spatially, the ecological environment quality exhibited a distribution pattern of "poor in the north and good in the south". (2) The area with improved ecological environment quality accounted for 81.50%, significantly higher than the degraded area (9.38%), indicating remarkable ecological improvement. (3) In single-factor detection, precipitation had the strongest explanatory power, followed by temperature and DEM. In interaction detection, the interaction between precipitation and temperature had the greatest influence, followed by the interaction between precipitation and DEM. The influence of climate and topographic factors gradually weakened, while the impact of human activities progressively strengthened. [Conclusion] From 2000 to 2024, the ecological environment quality in the Yellow River Source Park continuously improved. Precipitation, temperature and DEM are the main driving factors affecting ecological quality, and the ecological protection and restoration efforts carried out by humans have achieved remarkable results. Future work should focus on gradually advancing ecological management in key and challenging areas while ensuring the continuous improvement of the ecological environment in the study area.