The invention relates to the field of catalysts, in particular to a spherical aluminum-containing kaolin mesoporous composite, a supported catalyst, preparation methods and applications of the mesoporous composite and the supported catalyst as well as a preparation method of isopropyl oleate. Specifically, the invention discloses the spherical aluminum-containing kaolin mesoporous composite and the preparation method thereof, the spherical aluminum-containing kaolin mesoporous composite prepared with the method, the supported catalyst containing the spherical aluminum-containing kaolin mesoporous composite, the preparation method of the supported catalyst, the supported catalyst prepared with the method, as well as an application of the supported catalyst in an esterification reaction. The composite contains kaolin and a mesoporous molecular sieve material with a one-dimensional pore channel double-pore distribution structure, and aluminum accounts for 5%-30% by weight of the composite. When the supported catalyst prepared from the composite as a carrier is applied to the isopropyl oleate preparation process, the conversion rate of reaction raw materials can be remarkably increased.