In the process of aquaculture, we must first understand the good water quality standards in aquaculture, master the main parameters related to the quality of water quality and their functions, as well as the control technology for the corresponding parameters, which is particularly important to ensure the safety of aquaculture and product safety. Online monitoring of freshwater aquaculture water quality only needs to detect dissolved oxygen, water temperature, PH, ammonia nitrogen, nitrate and other indicators, while mariculture online water quality detection needs to add a salinity index. In addition, it is worth mentioning that in all the indicators of aquaculture water quality monitoring, dissolved oxygen is the most important item. When the dissolved oxygen in the water exceeds the limit, farmed animals can develop bubble disease, which manifests as difficulty breathing, bulging eyes, anemia, and even death. When the water is short of dissolved oxygen, the water quality of the pond will become muddy, and aquatic animals may produce a "floating head" phenomenon, and even all "flooding" in serious cases. In addition, dissolved oxygen will also follow the day and night, water temperature, season, light and other factors change, so you must focus on monitoring the dissolved oxygen in water this index.