Fluctuations in salinity have a significant impact on the ability of microorganisms to degrade target pollutants during water treatment. However, the interactions between salinity and microorganisms in industrial wastewater treatment have been explored in only a limited number of studies. Therefore, taking the actual coking wastewater treatment project as an example, the internal relationship between salinity, microbial community and pollutant removal was explored, and the technology salt reduction strategy was put forward. It was found that pollutants in wastewater treatment showed co-removal phenomenon and changes in salinity firstly elicited the response of denitrifying and phosphorus-removing carbon-utilizing microbial populations of Ottowia/Diaphorobacter, Alicycliphilus/Pseudomonas and Nitrosomonas/Nitrospira. The increase of salinity will lead to the destabilization of the microbial system, and the migration rate indicates that the aerobic unit (R