Boron powder is often used as a combustible agent in energetic materials due to its high calorific value， volume calorific value and clean combustion products. However， the surface oxide layer of boron powder makes it difficult to ignite and brings low combustion efficiency. In order to improve the ignition and combustion performances， boron powder was wetly milled in hot acetonitrile to remove the surface oxide layer for obtaining pre-treated boron powder with high activity， according to the good solubility of boron oxide in acetonitrile solvent. Acetonitrile and n-hexane were used as a dual control agent， and then the pretreated boron powder and highly active aluminum were performed a secondary ball milling to finally prepare the boron-aluminum composite powder with surface-activated boron. The morphological characteristics， thermogravimetric， ignition and combustion characteristics of boron and composite powder were studied. The results showed that the content of surface boron oxide of boron powder was reduced after pretreatment with acetonitrile， pretreatment boron powder was easier to react with oxygen when heated in air， and the percentage of mass increase was 25.6% more than that of untreated boron powder. After pretreatment with hot acetonitrile， the surface boron oxide content decreased， the active boron content increased， and the ignition and combustion performances were significantly improved. The mass of composite powder with boron-aluminum mass ratio of 60/40 increased by 93% when heated in air， the ignition temperature was 738.1 ℃ at low heating rate， and the particle combustion time was 11.2 ms.