[Objective] The spatio-temporal variation of ecological factors along the Yellow River in the Qingdao Water Diversion Project during 30 years of water diversion was quantified in order to provide a basis for the protection and management of the ecological environment. [Methods] Using remote sensing technology, the temporal and spatial variation of ecological factors (land use/cover, vegetation index and coverage, land surface temperature, soil moisture, and other factors) in the study area during 1990—2020 was analyzed to determine changes in the coastal ecological environment after the project operation. [Results] The areas classified as water, green land, and building land increased over time, while the area classified as unused land decreased significantly. Surface temperature fluctuated over the 30-year study period, while the temperature vegetation dryness index decreased from 0.758 to 0.433 and soil moisture increased significantly. These changes directly promoted high cover growth of vegetation. The mean value of the vegetation index increased by nearly 0.2. In addition, ecological factors were not independent of each other, and there was a certain degree of correlation. [Conclusion] The ecological environmental quality along the Water Diversion Project improved remarkably over 30 years, and urban and rural construction has rapidly developed during the project operation.