With the Boluo Station of the Dongjiang River Basin as a case study, the influence of water temperature in the Huizhou Reachunder different flow releasing conditions of the three large reservoirs was analyzed, the ecological operation goals based on water tempera -ture were discussed, and the joint ecological operation scheme of the three large reservoirs in March was proposed, by using 1D flow andwater temperature model. The results show that under the same proportion of outflow among three large reservoirs, the water temperatureincreases at the Boluo Station in March when the flow increases, but changes little; Under the same flow at Boluo station, the different outflow of three large reservoirs, especially Baipenzhu, have great effects on the water temperature in the Huizhou Reach. Combined with former research results, in condition of keeping the flow the of Boluo Station at 320m3/s, we recommend the least outflow of the BaipenzhuReservoir at 30m3/s in March, which is good for the ecology in the Huizhou Reach of the Dongjiang River.