Abstract: The present invention discloses a soil-structure improving bio-organic fertilizer and a preparation method thereof, and belongs to the technical field of biological fertilizers. The preparation method of the bio-organic fertilizer of the present invention includes the following steps: S1: aerobically fermenting cow dung-based organic materials to prepare a solid-state fermentation medium; S2: inoculating Bacillus subtilis fermentation broth and silicate bacteria fermentation broth into the solid-state fermentation medium for solid-state fermentation until the end of fermentation; and S3: after the fermentation is finished, extruding and granulating or directly sieving to prepare the soil-structure improving bio-organic fertilizer.