Abstract: Experimental research was carried out on the removal of ammonia nitrogen from the leaching solution of tailings reservoir in a gold mine and examined the treatment effect of ion exchange, chemical precipitation, breakpoint chlorination and new type reagent methods.The results show that the ion exchange and chemical precipitation methods don’t have good ammonia nitrogen treatment effect; the breakpoint chlorination and new type ammonia nitrogen removal reagent have good treatment performance on each pollutant in the leaching solution of tailings reservoir, and the two methods have nearly the same cost.However, considering the safety and secondary pollution, the new type reagent method is decided to be the optimal treatment method and the optimal conditions are: the dosage of No.1 and No.2 new type ammonia nitrogen removal reagent is 3 g/L and the reaction time is 30 min.