Aquaculture of captive-pond mode has higher sewage treatment efficiency and breeding density， which is due to the benefit of frequent removals of aquaculture waste in the captive tank. However， dissolved oxygen in high density aquaculture water is a concern for farmers. When the water temperature is high in summer， air aeration is inefficient， and the bubble-based aeration method cannot meet the requirements of oxygen supply. Gas-liquid mixed pump has a great performance on increasing dissolved oxygen in sewage aeration treatment. To explore whether gas-liquid mixed pump is suitable for the oxygen enhancement in the captive-pond mode， it is necessary to explore the optimal process parameters through experiments. In this study， the performances of the pump were tested under different water temperatures， outlet pressures and gas-water volume ratios， and the field tests were carried out in the pond captive tank （diameter 4 m， height 2 m， aquaculture water volume 20 m3）. The results showed that， under the conditions of outlet pressure of 0.25 MPa and gas-water volume ratio of 0.01 to 0.05， the dissolved oxygen in outlet water was inversely proportional to the water temperature （5.6 ℃， 13.5 ℃ and 30.3 ℃）， and the dissolved oxygen varied from 47.93 mg/L to 20.60 mg/L. The oxygen absorption efficiency was inversely proportional to the gas-liquid volume ratio， and the oxygen absorption efficiency varied from 91% to 33.7%. The dynamic efficiency was proportional to volumetric gas-liquid ratio and varied from 22.32 kg/（kW·h） to 55.12 kg/（kW·h）. Field test showed that， under the condition of fish oxygen consumption density of about 13.19 to16.49 kg/m³ ， when the pump’s working power was about 3 kW， the dissolved oxygen of each captive tank can reach 11 mg/L in the daytime and keep above 8 mg/L at night. The fluctuation of dissolved oxygen in the captive tank was within 0.2 mg/L， and the uniformity was good. The pump system is simple in structure and can work efficiently under high water temperature conditions.