The invention relates to a low-carbon ferromanganese production method using low-grade manganese mineral powder. The low-grade manganese mineral powder which has rich reserves is heated by a micro-wave oven, reduced by carbon, smelted at high temperature, purified by magnetic separation to directly prepare low-carbon ferromanganese. And the production method saves sintered agglomeration process with large energy consumption and serious pollution. The low-carbon ferromanganese with high purity is made through the steps that: the material is carefully chosen, crushed, fine- grinded, sieved, mixed, stirred, preheated by the micro-wave oven, pre-reduced through carbon monoxide, finally reduced, smelted at high temperature, cooled under the protection of nitrogen and purified by magnetic separation. The preparation method has the advantages of short technological process, less using equipment, being suitable for large- scale industrialization production, the yield rate can reach 98 percent, wherein manganese content is 75 percent and iron content is 20 percent, and the content of carbon is less than 0.5 percent; the content of harmful material sulfur is also less than 0.5 percent; the content of phosphor is less than 0.2 percent. The products have the advantages of low carbon, low phosphor and sulfur containing, no agglomeration, no pollution to environment. The method is the ideal ferromanganese direct production method using low-grade manganese mineral powder and fills up a scientific research blank in the field in China.