Abstract: Mariculture is an important factor of environmental pollution in coastal waters. Strengthening the control of mariculture tail water discharge is an important part of preventing and controlling pollution in coastal waters. In this paper, the pollution load of mariculture in Guangdong province is estimated by using the output of mariculture and the emission coefficient of main mariculture varieties and modes in 2020. The results show that in 2020, the total nitrogen and total phosphorus discharged from mariculture in Guangdong province to the marine environment are 5581 and 1009 tons respectively. There are great differences in the pollutant emissions along coastal cities. The impact of mariculture species on pollutant emissions is more restricted by mariculture mode, mariculture mode is the most important factor affecting the pollution load of mariculture. On this basis, this paper puts forward countermeasures and suggestions for the prevention and control of mariculture pollution from four aspects: strengthening the guidance of policy planning, promoting the development of green mariculture, strengthening the treatment of mariculture tail water and improving the ability of mariculture supervision, so as to provide a basis for strengthening the prevention and control of mariculture pollution improving and maintaining the environmental quality of coastal waters.