In order to increase the energy density of energetic materials, adding metal powder with higher energy is one of the effective methods. Boron powder has become a flammable agent with great application potential due to its high mass calorific value, volume calorific value and clean combustion products. However, the oxide layer on the surface of boron powder makes it difficult to ignite and bring it low combustion efficiency. Considering the fact that boron oxide is easily soluble in acetonitrile solvent, in this study, hot acetonitrile was used as a control agent in wet ball-milling to remove the surface oxide layer to obtain a pretreated boron powder with higher activity. Then, acetonitrile and n-hexane were used as double control agent in secondary ball milling on the pretreated boron powder and highly active metallic aluminum to finally prepare a boron-aluminum composite powder with activated boron surface. The morphological characteristics, thermos-gravimetric, ignition and combustion characteristics of the boron and composite powder were studied. It’s discovered that after pretreatment with hot acetonitrile, the content of boron oxide on the surface of boron powder is reduced, and it is easier to react with oxygen when heated in the air. After the pretreatment with hot acetonitrile, the content of boron oxide on the surface of composite powder is reduced. As the active boron content increases, its ignition performance is significantly improved, the ignition temperature is significantly reduced, and the combustion time is significantly increased.