The invention discloses a method for applying AM (arbuscularmycorrhizal) fungi to increasing crop yields, and belongs to the field of agricultural microbiology application technologies. The method includes 1), sowing crop seeds into cultivation pots; 2), inoculating the AM fungi on the surfaces of the crop seeds; 3), transplanting crop seedlings infected by the AM fungi to experimental fields 10-15 days after seedlings of the sown seeds emerge; 4), applying compound fertilizers to the root of each seedling 15-20 days after the seedlings are transplanted to the experimental fields, paying attention to preserving soil moisture thereafter and properly performing ridging; 5), harvesting crops after the crops are ripe. The method has the advantages that symbionts are set up among the AM fungi and root systems of the crops, so that absorption areas of the root systems of the crops can be expanded, inorganic and organic fertilizers in soil can be sufficiently utilized, loss of the fertilizers and environmental pollution can be reduced, operation is facilitated, the agricultural cost is low, harden soil can be rehabilitated, the crop yields can be obviously increased as known from contrast experiments, and the like.