The invention provides a fermentation process of low-moisture organic fertilizer. The fermentation process includes the following steps: (1), adding microbial agents into rapeseed cakes, and evenly stirring to control the water content of the rapeseed cakes to be 32-38%; (2), adding magnesium oxide into the rapeseed cakes; (3), performing fermentation to obtain the low-moisture organic fertilizer. The fermentation process has the advantages that pH in the fermentation process can be increased, the pH value of the fermentation process does not need further adjustment, the technological process is shortened, labor cost is reduced, and fermentation of rapeseed meal is benefited; the pH value after fermentation is 6-8, and the low-moisture organic fertilizer is suitable for serving as a high-quality organic fertilizer raw material resource; through addition of the magnesium oxide, fermentation process cycle is shortened, and the water content of the rapeseed meal is reduced; through addition of the microbial agents, reproduction speed is high, activity of other beneficial bacteria can be improved, and fermentation cycle can be further shortened.