【Objective】Flooding and organic matter addition to anaerobic treatment has been proven to reduce excess salt in greenhouse soil and improve soil quality. There are many types of organic matter in the field, so how to select effective materials is a key problem. 【Method】Six types of organic materials with different carbon (C), nitrogen (N) and sulfur (S) proportions were selected and tested at two rates of 2 g·kg?1and 8 g·kg?1. 【Result】Flooding and organic matter addition can quickly create a reducing environment for soil. On the first day of incubation, the redox potential (Eh) rapidly decreased to around 0 mV, accompanied by a rapid decline in soil electrical conductivity (EC), SO42?, and NO3??N. By the end of the anaerobic cultivation process, almost all NO3??N had been removed, and the variety and amount of organic matter added had no significant effect on NO3??N removal. The effect of rapeseed straw with low C/S ratio on SO42? removal was weak, with a removal rate of 58%. A high C/S ratio maize straw can reduce SO42? from an initial concentration of 153 mg·kg?1 to 17 mg·kg?1, a decrease of 89%. Different amounts of added materials only affect the speed of SO42? removal, but not the final removal effect. At the end of cultivation, there was no significant difference in SO42? removal between treatments with 2 g·kg?1 and 8 g·kg?1 of organic matter added. The content of other forms of sulfur did not change significantly, indicating that most of the reduced SO42? was converted into organic sulfur. 【Conclusion】For the purpose of remediating excess SO42? in soil, it is recommended to use organic materials with high C/S such as maize straw and set the addition amount at 2 g·kg?1 to obtain good results.