The amount of the dissolved oxygen in the water is an important index for the fishery breeding. This design is intended to avoid the negligence in fishery breeding because farmers failed to increase the oxygen to the pond, which led to the death of fish, also discussed the influence of algae water pollution, temperature and water depth on the determination. The design using acidic gel electrolyte original battery coated in oxygen sensors as oxygen sensor，AT89S52 SCM system as the oxygen determination and control system, SCM control relay to control the opened and closed of aerator. To improve the accuracy of oxygen collection, this design uses three oxygen sensor at different positions turns sequential sampling in the pond, by the A/D converter into SCM and corresponding control signal. If the average value of oxygen content in the pool below the lowest oxygen resistance of fish aerator would be opened, to ensure the lowest oxygen content so that fish will avoid death. Avoid the economic losses caused by the fish death as farmers fail to open aerator timely, that because of the low oxygen content cause by the sudden changes of light, temperature, pressure and so on. At the same time the design will always show the oxygen content at all times, so that oxygen contents can be adjusted according to the numerical value in the pond, to achieve optimal oxygen content and improve the standard of fish feed conversion rate and growth rate.