Preparation process for flaky alumina with great diameter-thickness ratio

The invention discloses a preparation process for flaky alumina with a great diameter-thickness ratio. The preparation process comprises the following steps of: adding fused salt in alumina powder; adding a template agent; adding a shaping agent and then uniformly mixing; filling a mixture into a crucible with a cover; after reacting at the set temperature, washing soluble salts with hot water; and dissolving an impurity phase in a hydrofluoric acid solution and washing and drying to obtain the flaky alumina. According to the method, the template agent and the shaping agent are added to obtain the regular flaky alumina with the great diameter-thickness ratio. The method has the characteristics of simple process and easiness for industrial production. The flaky alumina prepared by the invention can be used as a composite material enhanced phase, a high-grade abrasive, a substrate of pearl pigment and filler of a polymer material.