The invention provides an alpha-alumina carrier. The most probable pore size of the alpha-alumina carrier is 3.00-9.50 microns, and the specific surface area is 0.15-1.20m<2>/g. The macroporous alpha-alumina carrier is used for catalyzing reaction, in particular for catalyzing epoxidation of ethylene to prepare ethylene oxide, and the heat produced in the catalysis process can be immediately transferred and evacuated so as to guarantee the stabilization of the catalyst and the stable operation of a reaction device. The invention further provides a method for preparing the alpha-alumina carrier. The method comprises the following steps: step A, uniformly mixing gibbsite, pseudo alumina monohydrate, a fluorine-containing compound and alkaline earth salt to obtain solid powder, and adding an adhesive and water to obtain a mixture; step B, kneading, forming, drying and roasting the mixture of the step A to obtain the alpha-alumina carrier, wherein the mass of the fluorine-containing compound is 5-15% of the solid powder.