Affected by the reservoir, the changes of ecological indicators in Yichang were significantly higher than those in the downstream stations, and the impact of the TGR on the MRYR generally showed a decrease in space along the route (Figure 10). At the same time, the changes of ecological surplus and ecological deficit of the three monitoring sections in the MRYR are synchronized in the time domain, and the peak-to-valley changes of ecological surplus and ecological deficit also have a significant negative correlation. The operation of the TGR to a certain extent leads to an average increase of 0.015 in annual ecosurplus and an average decrease of 0.002 in ecodeficit, which are generally beneficial to the ecological hydrological regime in the MRYR (Table 7). Because the application of the TGR was mainly carried out in spring and winter, the ecological surplus of downstream reservoir increased significantly, which increased by 0.057 and 0.11, respectively. In the summer flood season, the TGR flood control task requires its peak flow. When the inflow is lower than the flood control target, the water level of the reservoir area is reduced to 145 m by increasing the discharge, and then the water is equal to the discharge. Therefore, the TGR has little influence on the downstream ecological indicators in this period, and it mainly contributes to the reduction of the ecological deficit by 0.01. In autumn, in order to meet the requirements of power generation, the reservoir began to store water, and the discharge was much lower than the inflow, resulting in a decrease in the downstream ecological surplus and a substantial increase in the ecological deficit, and the growth rate reached the annual maximum (0.051).