The invention relates to an aripiprazole long-acting controlled-release microgranule injection and a preparation method thereof. The aripiprazole long-acting controlled-release microgranule injection is prepared from the following components in percentage by weight: 1-50% of aripiprazole, 48-97% of a high-molecular polymer, 1-5% of a medicine release characteristic regulator, and 0.01-0.5% of an emulgator, wherein the medicine release characteristic regulator is a mixed solvent of benzyl alcohol and dimethyl sulfoxide, and benzyl alcohol accounts of 70%-99% of the medicine release characteristic regulator based on the weight. The aripiprazole long-acting controlled-release microgranule injection has the advantages of controllable grain size, high medicine loading capacity, high encapsulation efficiency, low initial burst release, complete release, and continuous medicine release for one month or a longer time. According to the aripiprazole long-acting controlled-release microgranule injection, the medicine release characteristic regulator can regulate the medicine release characteristic of the preparation, so that the release amount of the medicine achieves 90% or above, the medicine is uniformly distributed in the microgranules and exists in the form of molecules, and therefore, the problem that during the release process, the medicine gradually forms crystals, and consequently, the release becomes slow is solved.