The invention discloses an organic fertilizer fermentation inoculant and application. The inoculant is composed of a primary fermentation inoculant body and a secondary fermentation inoculant body. The primary fermentation inoculant body comprises bacillus subtilis, bacillus licheniformis, trichoderma viride, aspergillus oryzae, pseudomonas, trichoderma koningii, geotrichum candidum, long spiny shells, ascomycetes, thermomyces lanuginosus and thermobifida fusca. The secondary fermentation inoculant body comprises halophilic bacteria, alkalophilic bacteria, azotobacter chroococcum, bacillus megatherium, streptomyces griseus, bacillus thuringiensis, brevibacillus laterosporus and bacillus mucilaginosus. Time for fermenting organic fertilizer with cow dung as the raw material can be effectively shortened, and diseases and insect pests in the fertilizer can be eliminated. Meanwhile, alkalophilic bacteria and bacillus thuringiensis are added so that the fermentation inoculant can adapt to saline-alkali soil and can prevent diseases and insect pests of plants, and the prepared organic fertilizer can improve the soil structure, reduces the salt content and the pH value in soil, improves soil fertility and is particularly beneficial to improvement of saline-alkali soil.