The ecological quality of arid and semi-arid regions is fragile, and research on multi-factor and long-term dynamic change of ecological quality can provide scientific basis for the ecological construction and regional sustainable development in arid and semi-arid regions. Based on the remote sensing ecological index (RSEI), according to the characteristics of arid and semi-arid regions, five indexes of greenness (NDVI), humidity (WET), heat (LST), dryness (SI) and salinity (SI-T) were coupled, and the modified remote sensing ecological index (mRSEI) model was proposed to dynamically evaluate the ecological quality of the Tabu River Basin from 1986 to 2022. Mann-Kendall mutation test, Theil-Sen (T-S) analysis, and Mann-Kendall trend analysis were used to explore the temporal and spatial changes of ecological quality. Then, ERA5 meteorological data was introduced to explore the correlation between climatic factors and mRSEI ecological indicators at pixel by pixel level. Results showed that:(1) Compared with RSEI, mRSEI could better integrate the information contained in each ecological component, and the model was more stable and reliable. (2) The negative influence of mRSEI mainly came from the salinity index (SI-T), and the average correlation coefficient was -0.922, which was greater than that of the dryness index and the heat index, indicating that the introduction of salinity index was of great significance for the ecological quality evaluation in arid and semi-arid areas. (3) The mRSEI was between 0.179 and 0.423 in the study time series, and the ecological quality showed a downward trend (Slope=-0.0014,P<0.05). (4) The results of trend analysis showed that 84.37% of the ecological quality did not change in the Tabu River Basin, and in the other 15.63%, the degraded area accounted for much more than the area with improved ecological quality. On the whole, the ecological quality of the study area showed a trend of degradation. (5) The correlation between climatic factors and mRSEI showed that precipitation was positively correlated with mRSEI (r=0.411-0.807), and average annual temperature was negatively correlated with mRSEI (r=-0.824--0.398); Besides the results of temporal correlation analysis showed that temperature was the main controlling factor of ecological quality in the study area. (6) Although human factors may disturb the ecological quality of the Tabu River Basin, they do not play a decisive role. Based on the mRSEI, it can scientifically monitor the spatial distribution of ecological quality in arid and semi-arid areas and accurately grasp the trend of ecological quality change, which can provide theoretical support for ecological protection in arid and semi-arid regions.