Abstract: In order to control the growth speed and volume of the composite in the DIMOX, the method of added metal or alloy is adopted with the help of pressure head, with the result that the composition of the remanent aluminum alloy metal can be adjusted and continuously contacted with the growing Al₂O₃/Al composite material layer obtained by directed metal oxidation growth. The effect of the additional alloy composition on the oxidation growth of Al-3Mg-10Si alloy was studied. The results show that the additional pure aluminum or aluminum alloy with low Mg and Si content can reduce Mg content of aluminum alloy melt, shorten the time of reaching Al₂O₃-(Al, Mg)phase zone of the alloy melt of growth forward position, promote mass transmission process, accelerate material growth, and be favorable to obtain more larger volume composite material.