Abstract: During the 13 th Five-Year Plan period, the dissolved oxygen concentration of the surface water in Jinshan District continued to rise from 2016 to 2020. In 2018, one monitoring section reached the category Ⅲ of the water standard. There were 11 sections in 2019. In 2020, eight sections reached Class Ⅲ water. Water pollution prevention input and pollution emission reduction had an impact on the increase of dissolved oxygen concentration. Water pollution prevention input had a significant effect on the increase of dissolved oxygen concentration in the surface water in Hongqi Port.