Because Mn-Si-Al alloy is easy to be pulverized,the storage and transportation of the products are inconvenient,and the application effect of the deoxidizer is also seriously affected. The pulverization mechanism,composition control and the method to solve the pulverization of Mn-Si-Al alloy are discussed. In order to make full use of a large number of sieves produced by manganese alloys,manganese silicon aluminum composite alloys were produced. Tests have shown that using siliconmanganese screening matching with medium carbon ferromanganese screening can produce qualified Mn-Si-Al alloy. It can delay the pulverization time of the alloy by ingot and sealing moisture-proof packaging.