Study on catalytic combustive reaction of dimethyl ether as a new fuel was presented. Hexaaluminate catalysts were used to reduce ignition temperature so that dimethyl ether completely combusted at low temperature. Hexaaluminate catalysts MnLaAl11O19-δ were prepared by reverse microemulsion method. Crystalline phase and structure of the catalyst were analysed by means of TG-DTA, XRD and BET. The results show that the hexaalunminate is of magnetoplumbite structure when La is taken as mirror plane cation. Hexaalunminate phase is formed slowly via 1050 ℃ calcined for 4 h and it can keep hexaaluminate phase and high surface area of 48 m2·g-1 even calcined at 1200 ℃ for 2h. Catalytic activity of MnLaAl11O19-δ was tested in combustion reaction of dimethyl ether. It shows that hexaaluminate is of high activity with T 10% at 170 ℃ and almost 100% conversion at 370 ℃.