This paper uses sulfur autotrophic denitrification to treat nitrate\|polluted underground water so as to explore the impacts of Cu2+ and Fe2+ ion addition on denitrification. Addition of Fe2+ ions at 0.10% and 0.20% or Cu2+ ion at 0.05% can effectively remove the nitrate and promote the denitrification rate. After 216 hours in reaction, nitrate removal rate reaches at 97%, up to 99%. Appropriate addition of metal ions may significantly reduce the accumulation of sulfates. In the entire reaction, composite material provides sufficient alkalinity for denitrification system, which guarantees the efficiency of denitrification reaction.