Electrolytic manganese (EMM) industry with a large amount of waste water and high density of pollution, belonging to the high polluting industries, is one of the main threats of pollution control and emission reduction. Based on the analysis of the pollution prevention status of EMM industry, index system for pollution prevention technological evaluation was built. This paper obtained weight and quantifying value of each index with analytic hierarchy process (AHP), and evaluated the technology of pollution prevention using comprehensive index. On this basis, prediction of pollution reduction potential of best available technologies (BATs) was made using bottom-up model. The result showed the total emissions of waste water would be reduced more than 2.7×106 t, the reduction of ammonia nitrogen emission could be 6.6×104 t, recovered manganese and potassium bichromate could be 1.9×105 t and 3.747×107 t respectively, the reduction of manganese slag emission could be 4×106 t in 2015, comparing to the baseline year 2010. It also proved that clean production technology was superior to end treatment, and clean production technology would be widely used.