To provide a method for producing a granular agrochemical composition excellent in mixing uniformity, obtained by mixing granule groups consisting of granules containing ≥2 kinds of different agrochemicals.

The granular agrochemical composition is produced by mixing the granule groups consisting of granules containing ≥2 kinds of different agrochemicals by a horizontal mixing process of performing a total counter current mixing by moving the positions of the granule group in horizontal direction performed by a reduction vessel 1, an up and down mixing process of performing the total counter current mixing by moving the positions of the granule groups in up and down direction performed by a dynamic mixer 2, and a micro-mixing process performing a local diffusion and mixing by the sliding or collision of granules each other performed by a static mixer 3.