This creation discloses a device for controlling dissolved oxygen in water. The gas is delivered into the device by an external gas supply device, and the water flow sucked through the self-priming device is mixed with the ultrafine bubbles generated by an ultrafine bubble generation device to become super The fine bubble water is released into the external water tank, and the water in the external water tank is continuously provided with sufficient dissolved oxygen to supply the aquatic organisms to continuously breathe to maintain a healthy state, and the dissolved oxygen in the water in the external water tank can also be removed； so that the dead aquatic organisms It will not spoil due to oxidation, and achieve the effect of autonomously controlling the oxygenation or deoxygenation of the water in the external water tank.本創作公開了一種水中溶氧控制裝置，藉由外部氣體供應裝置將氣體輸送至本裝置內，並透過自吸式裝置吸取的水流與一個超微細氣泡產生裝置所產生的超微細氣泡混合成為超微細氣泡水釋放至外部水槽中，持續提供外部水槽內的水中有足夠的溶氧供應水中生物持續呼吸保持健康狀態，亦可將外部水槽內之水分中之溶氧去除；使已死亡的水中生物不會因氧化而腐敗，達到對外部水槽內之水分自主控制增氧或除氧的功效。
