The invention discloses a method for producing ultrathin fermentation bed bacteria, and belongs to the field of microorganism fermentation. Adopted strains are rhizopus oryzae, aspergillus niger, candida utilis, bacillus licheniformis, bacillus subtilis and enterococcus faecium; and the method comprises the following steps of: performing single pure culture on the strains to obtain strains for producing; mixing the strains uniformly, inoculating into a koji plate for culture and fermentation, and fermenting for 2 to 3 days at the pH value of 6.5-7.5; and drying, crushing and packaging to obtain the ultrathin fermentation bed bacteria. The ultrathin fermentation bed bacteria have high viable count of microbes, total viable count of fungi of more than 0.5 billion / gram and the total viable count of bacteria of 4.5 billion / gram, reasonable in type collocation, and high in adaptivity; and when the ultrathin fermentation bed bacteria are matched with an ultrathin fermentation bed technology, old pig pens are not needed to be transformed basically, the cost of newly-built pig pens is obviously reduced, the using amount of a padding for building the fermentation bed is small, the cost is low, the temperature of the fermentation bed can be controlled, the fermentation bed is warm in winter and cool in summer, the problem that the conventional fermentation bed is humid and hot in summer is obviously solved, and the used padding for the fermentation bed is a good-quality microbial organic fertilizer.